Answer:
Step-by-step explanation:
The x intercepts occur when the quadratic is equal to zero.
1.
x^2-7x-18=0 factoring we get
(x-9)(x+2)=0 since multiplying anything by zero is zero the x intercepts occur when
x=-2 and 9
2.
2b^2+17b+21=0
2b^2+14b+3b+21=0
2b(b+7)+3(b+7)=0
(2b+3)(b+7)=0
b=-7 and -1.5