Question

What is the value of c so that -10 and 10 are both solutions of x2 -c=70?

Answer 1

Answer:

c = 30

Step-by-step explanation:

since:

${(10)}^{2} = { (- 10)}^{2}$

once we find a c value for 10, we know that it will work for - 10 as well

${x}^{2} - c = 70$

we can sub in 10 to get

${10}^{2} - c = 70 \\ c = 100 - 70 \\ c = 30$