SOLUTION: solve b2-7b+12=0

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Question 195719: solve
b2-7b+12=0
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
b%5E2-7b%2B12=0 Start with the given equation.


Notice we have a quadratic equation in the form of Ab%5E2%2BBb%2BC where A=1, B=-7, and C=12


Let's use the quadratic formula to solve for b


b+=+%28-B+%2B-+sqrt%28+B%5E2-4AC+%29%29%2F%282A%29 Start with the quadratic formula


b+=+%28-%28-7%29+%2B-+sqrt%28+%28-7%29%5E2-4%281%29%2812%29+%29%29%2F%282%281%29%29 Plug in A=1, B=-7, and C=12


b+=+%287+%2B-+sqrt%28+%28-7%29%5E2-4%281%29%2812%29+%29%29%2F%282%281%29%29 Negate -7 to get 7.


b+=+%287+%2B-+sqrt%28+49-4%281%29%2812%29+%29%29%2F%282%281%29%29 Square -7 to get 49.


b+=+%287+%2B-+sqrt%28+49-48+%29%29%2F%282%281%29%29 Multiply 4%281%29%2812%29 to get 48


b+=+%287+%2B-+sqrt%28+1+%29%29%2F%282%281%29%29 Subtract 48 from 49 to get 1


b+=+%287+%2B-+sqrt%28+1+%29%29%2F%282%29 Multiply 2 and 1 to get 2.


b+=+%287+%2B-+1%29%2F%282%29 Take the square root of 1 to get 1.


b+=+%287+%2B+1%29%2F%282%29 or b+=+%287+-+1%29%2F%282%29 Break up the expression.


b+=+%288%29%2F%282%29 or b+=++%286%29%2F%282%29 Combine like terms.


b+=+4 or b+=+3 Simplify.


So the answers are b+=+4 or b+=+3