Question

1. Find the sum and the product of the roots of the following equations.

Answer 1

1- sum=6
    Product=5
2-   sum= -r/k
    Product=p

3-   sum= 5/3
    Product=0

4-  sum=0
    Product=-25/8

Answer 2

Solution :

i ) Compare x² - 6x + 5 = 0 with

ax² + bx + c = 0 , we get

a = 1 , b = -6 , c = 5

Sum of the roots = -b/a = -(-6)/1 = 6

Product of the roots = c/a = 5/1 = 5

ii ) Compare kx² + rx + pk = 0 with

ax² + bx + c = 0 , we get

a = k , b = r , c = p

Sum of the roots = -b/a = -r/k ,

Product of the roots = c/a = p/k

iii ) Given 3x² - 5x = 0

a = 3 , b = -5 , c = 0

sum of the roots = -b/a = -(-5)/3 = 5/3

product of the roots =c/a = 0

iv ) Given 8x² - 25 = 0

a = 8 , b = 0 , c = -25

sum of the roots = -(-b)/a = 0

product of the roots = c/a = -25/8

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