SOLUTION: I need help to some questions and I need help badly can anyone help me please the questions are as followed:if a=0.65 and b=1.28 and c=-5over2 evaluate - a(-b)+c but the answer I g

Algebra ->  Equations -> SOLUTION: I need help to some questions and I need help badly can anyone help me please the questions are as followed:if a=0.65 and b=1.28 and c=-5over2 evaluate - a(-b)+c but the answer I g      Log On


   

Question 68251: I need help to some questions and I need help badly can anyone help me please the questions are as followed:if a=0.65 and b=1.28 and c=-5over2 evaluate - a(-b)+c but the answer I get out of it is three different ones every time its between -4.43,-1.87,and -0.57 I'm confused.The next one is solve the equation for q:6+[Q-2]=-1.The next one is if p=0.75 and q=-1.6,evaluate:p+q-(-0.7).And the last one is solve the equation for b:3over5=9over10b.Thank you for whoever can help thanks
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
need help to some questions and I need help badly can anyone help me please the questions are as followed:
:
if a=0.65 and b=1.28 and c=-5 over 2 evaluate - a(-b)+c
Since the answer is in decimals change -5/2 to -2.5 (c)
:
-0.65(-1.28) + (-2.5)
:
+.832 - 2.5; minus times a minus is a plus, plus a minus is a minus
:
-1.668
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solve the equation for q:
6 + [Q-2] = -1
:
Get rid of the brackets:
6 + Q - 2 = -1
:
Q + 4 = -1; did the math on the left
:
Subtract 4 from both sides:
Q = - 1 - 4
:
Q = -5
:
you can check that in the original equation:
6 + [Q-2] = -1
6 + [-5-2] = -1
6 + (-7) = -1
6 - 7 = -1
:
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if p=0.75 and q=-1.6, evaluate:
p + q -(-0.7)
:
Remember a minus a minus is a plus, remove the brackets and you have:
p + q + 0.7
:
Substitute for p & q
.75 + (-1.6) + .7
:
.75 - 1.6 + .7 = -.15
:
:
solve the equation for b: 3 over 5= 9 over 10b
3%2F5 = 9%2F%2810b%29
:
We want to get rid of the denominators, mult both sides by 10b
10b%283%29%2F5 = 10b%289%29%2F%2810b%29
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After canceling we have:
2b(3) = 9
:
6b = 9
:
b = 9/6
:
b = 3/2 or 1.5
:
Check, substitute 1.5 for b:
3%2F5 = 9%2F%2810%281.5%29%29
3%2F5 = 9%2F%2815%29 proves that b = 1.5
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Hope this helps!
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