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The equation x2 – 1x – 90 = 0 has solutions {a, b}. What is a + b?

A) -19
B)-9
C)1
D)10

Respuesta :

Panoyin
                        x² - x - 90 = 0
            x² - 10x + 9x - 90 = 0
        x(x - 10) + 9(x - 10) = 0
x(x) - x(10) + 9(x) - 9(10) = 0
                  (x + 9)(x - 10) = 0
     x + 9 = 0    or    x - 10 = 0
         - 9  - 9            + 10 + 10 
           x = -9       or       x = 10

{a, b} = {-9, 10}

a + b = -9 + 10
a + b = 1

The answer is C.

The value of a+b is 1.

What is equation?

An equation is a formula that expresses the equality of two expressions, by connecting them with the equals sign =.

Given : x² - x - 90 = 0

x² - 10x + 9x - 90 = 0

x(x - 10) + 9(x - 10) = 0

(x + 9)(x - 10) = 0

x + 9 = 0    or    x - 10 = 0

x = -9       or       x = 10

{a, b} = {-9, 10}

Hence, a+b = -9 +10= 1

Learn more about equation here:

https://brainly.com/question/10413253

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