Answer:
but where is que
Step-by-step explanation:
i don't see the question
So you always want to pull out the gcf first but since there isn't one, we can move on.
so we can make an acb chart which is multiplying the a value and the c value and find factors that of that product that will equal the b value.
a value is 2
c value is -15
b value is 7
-30 factors to equal 7 = 10, -3
10 - 3 = 7
so the factors 10 and -3 work.
so now you make 2 separate parenthesis with one of the factors and one x. and it should be set equal to 0.
(x+10)(x-3) = 0
now solve for x in each separate parenthesis.
x = -10
x = 3
those r the roots
hope this helps
Answer:
see explanation
Step-by-step explanation:
Given
x² - 3x - 40 = 0
Consider the factors of the constant term (- 40) which sum to give the coefficient of the x- term (- 3)
The factors are - 8 and + 5, since
- 8 × 5 = - 40 and - 8 + 5 = - 3, thus
(x - 8)(x + 5) = 0 ← in factored form
Equate each factor to zero and solve for x
x - 8 = 0 ⇒ x = 8
x + 5 = 0 ⇒ x = 5
------------------------------------------------------
Given
4x² - 81 = 0 ← this is a difference of squares and factors in general as
a² - b² = (a + b)(a - b), thus
4x² - 81
=(2x)² - 9²
= (2x + 9)(2x - 9) = 0 ← in factored form
Equate each factor to zero and solve for x
2x + 9 = 0 ⇒ 2x = - 9 ⇒ x = - 
2x - 9 = 0 ⇒ 2x = 9 ⇒ x = 