Question

What is the value of c so that -9 and 9 are both solutions of x2+c=103

Answer 1

Answer:

$c=22$

Step-by-step explanation:

Given equation:

$x^2+c=103$

Solutions: -9 and 9

To solve for $c$

Solution:

The solutions of the equation means $x=-9$ and $x=9$

We will plugin the solutions in the equation and solve for $c$

1)  when $x=-9$

$(-9)^2+c=103$

$81+c=103$

Subtracting both sides by 81.

$81+c-81=103-81$

∴ $c=22$

2)  when $x=9$

$(9)^2+c=103$

$81+c=103$

Subtracting both sides by 81.

$81+c-81=103-81$

∴ $c=22$

So, for both solutions we get $c=22$