Im not sure but I think u have to add or multiply
x² + bx - 81
there are 2 formula that fit this equation :
>> x² - a² = (x+a)(x-a)
or
>> x² + 2ax² + a² = (x+a)(x+a)
because the last value of our equation is negative value therefore we have to use the first formula >> x² - a² = (x+a)(x-a)
step:
x² + bx - 81
x² + bx - 9²
because we have to follow the first formula x² - a² therefore bx = 0
x² + bx - 9²
bx = 0
b = 0
The answer to your question is C. I hope this has helped
2 consecutive odd integers.....x and x + 2.....the product means multiply....the sum means add.
x(x + 2) = 4(x + x + 2) - 1
x^2 + 2x = 4(2x + 2) - 1
x^2 + 2x = 8x + 8 - 1
x^2 + 2x = 8x + 7
x^2 + 2x - 8x - 7 = 0
x^2 - 6x - 7 = 0
(x - 7)(x + 1) = 0
x - 7 = 0 x + 2 = 7 + 2 = 9
x = 7
x + 1 = 0 x + 2 = -1 + 2 = 1
x = -1
there can be 2 answers for this....
(1) 7 and 9
(2) -1 and 1
