Question

What is the value of x if x * x + 2x - 35 = 0?

Answer 1

`\\ \sf\longmapsto x^2+2x-35=0`

`\\ \sf\longmapsto x^2-7x+5x-35=0`

`\\ \sf\longmapsto x(x-7)+5(x-7)=0`

`\\ \sf\longmapsto (x+5)(x-7)=0`

`\\ \sf\longmapsto x=-5\:or\:x=7`

Answer 2

5 or -7

Explanation:

Use the quadratic formula to solve for x:

`x^2+2x-35=0\\x=(-b\±√(b^2-4ac) )/(2a) \\x=(-2\±√(2^2-4(1)(-35)) )/(2(1)) \\x=(-2\±√(4+140) )/(2)\\x=(-2\±√(144) )/(2)\\x=(-2\±12)/(2)\\x=-1\±6`

Simplify to get two real solutions, 5 and -7.