document.write( "Question 867363: I have no clue how to do these problems. Please help \r
\n" ); document.write( "\n" ); document.write( "Find the expression.
\n" ); document.write( "1.) u = (-3,-2), v = (-8, -11) Find u-v
\n" ); document.write( "choices: a.) (-5,-19) b.) (-1,3) c.) (5,9) d.) (-11,-13)\r
\n" ); document.write( "\n" ); document.write( "2.) w = (-1,3) and v = (0,1) Find ||-4w -v||
\n" ); document.write( "choices: a.) 185 b.)sqrt 185 c.) sqrt 155 d.) 155\r
\n" ); document.write( "\n" ); document.write( "3.) u = 4i - 6j and v = -5i - 21j; Find ||v-u||
\n" ); document.write( "choices: a.) sqrt 34 b.) -2 sqrt 34 c.) 3 sqrt 35 d.) 3 sqrt 34\r
\n" ); document.write( "\n" ); document.write( "4.) if v = 3i + j and w = -10i + j; Find ||v + w||
\n" ); document.write( "choices: a.) sqrt 130 b.) 13 c.) sqrt 53 d.) sqrt 111\r
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Algebra.Com's Answer #522975 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
Find the expression.
\n" ); document.write( "1.) u = (-3,-2), v = (-8, -11) Find u-v
\n" ); document.write( "choices: a.) (-5,-19) b.) (-1,3) c.) (5,9) d.) (-11,-13)\r
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\n" ); document.write( "\n" ); document.write( "Simply subtract the corresponding elements like so:\r
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\n" ); document.write( "\n" ); document.write( "u - v = (-3,-2) - (-8, -11)\r
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\n" ); document.write( "\n" ); document.write( "u - v = (-3-(-8),-2-(-11))\r
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\n" ); document.write( "\n" ); document.write( "u - v = (-3+8,-2+11)\r
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\n" ); document.write( "\n" ); document.write( "u - v = (5,9) which is choice C
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\n" ); document.write( "2.) w = (-1,3) and v = (0,1) Find ||-4w -v||
\n" ); document.write( "choices: a.) 185 b.)sqrt 185 c.) sqrt 155 d.) 155\r
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\n" ); document.write( "\n" ); document.write( "First multiply everything in w by -4 to get\r
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\n" ); document.write( "\n" ); document.write( "w = (-1,3)\r
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\n" ); document.write( "\n" ); document.write( "-4w = -4(-1,3)\r
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\n" ); document.write( "\n" ); document.write( "-4w = (-4(-1),-4(3))\r
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\n" ); document.write( "\n" ); document.write( "-4w = (4,-12)\r
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\n" ); document.write( "\n" ); document.write( "Then subtract off v\r
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\n" ); document.write( "\n" ); document.write( "-4w - v = (4,-12) - (0,1)\r
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\n" ); document.write( "\n" ); document.write( "-4w - v = (4-0,-12-1)\r
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\n" ); document.write( "\n" ); document.write( "-4w - v = (4,-13)\r
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\n" ); document.write( "\n" ); document.write( "Finally, find the length of this vector using the formula ||x|| = sqrt(a^2 + b^2) where x = (a,b)\r
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\n" ); document.write( "\n" ); document.write( "So,\r
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\n" ); document.write( "\n" ); document.write( "||-4w - v|| = sqrt((4)^2 + (-13)^2)\r
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\n" ); document.write( "\n" ); document.write( "||-4w - v|| = sqrt(16+169)\r
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\n" ); document.write( "\n" ); document.write( "||-4w - v|| = sqrt(185) which is choice B
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\n" ); document.write( "3.) u = 4i - 6j and v = -5i - 21j; Find ||v-u||
\n" ); document.write( "choices: a.) sqrt 34 b.) -2 sqrt 34 c.) 3 sqrt 35 d.) 3 sqrt 34\r
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\n" ); document.write( "\n" ); document.write( "First compute v-u\r
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\n" ); document.write( "\n" ); document.write( "v-u = (-5i - 21j) - (4i - 6j)\r
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\n" ); document.write( "\n" ); document.write( "v-u = -5i - 21j - 4i + 6j\r
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\n" ); document.write( "\n" ); document.write( "v-u = -9i - 15j\r
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\n" ); document.write( "\n" ); document.write( "Then find the length of this vector\r
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\n" ); document.write( "\n" ); document.write( "||v-u|| = sqrt((-9)^2+(-15)^2)\r
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\n" ); document.write( "\n" ); document.write( "||v-u|| = sqrt(81+225)\r
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\n" ); document.write( "\n" ); document.write( "||v-u|| = sqrt(306)\r
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\n" ); document.write( "\n" ); document.write( "||v-u|| = sqrt(9*34)\r
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\n" ); document.write( "\n" ); document.write( "||v-u|| = sqrt(9)*sqrt(34)\r
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\n" ); document.write( "\n" ); document.write( "||v-u|| = 3*sqrt(34) which is choice D
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\n" ); document.write( "4.) if v = 3i + j and w = -10i + j; Find ||v + w||
\n" ); document.write( "choices: a.) sqrt 130 b.) 13 c.) sqrt 53 d.) sqrt 111\r
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\n" ); document.write( "\n" ); document.write( "Start by adding vectors v and w\r
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\n" ); document.write( "\n" ); document.write( "v + w = (3i+j) + (-10i+j)\r
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\n" ); document.write( "\n" ); document.write( "v + w = 3i+j-10i+j\r
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\n" ); document.write( "\n" ); document.write( "v + w = -7i+2j\r
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\n" ); document.write( "\n" ); document.write( "Now compute the length\r
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\n" ); document.write( "\n" ); document.write( "||v + w|| = sqrt(a^2 + b^2)\r
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\n" ); document.write( "\n" ); document.write( "||v + w|| = sqrt((-7)^2 + (2)^2)\r
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\n" ); document.write( "\n" ); document.write( "||v + w|| = sqrt(49+4)\r
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\n" ); document.write( "\n" ); document.write( "||v + w|| = sqrt(53) which is choice C
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