I have a friend who is really stressed and depressed and couldn't get this done. it's 2am for them so they're going to sleep. I want to help them in every way I can.

Step-by-step explanation:

first problem:

3 is a solution to x^2=9, so to a, b, c and d

second problem

-2 is a solution to:

a, b, c and d because (-2)^2=4, 4=4, b) 5*(-2)^2=5*4=20 and so on

basically to all choices

the third, solve the equations:

x^2=1, =, x=1

x^2=81 sqrtx^2=sqrt81, x=+and -9

4x^2=1 divide by 4 , x^2=1/4, x=+&- 1/2 (plus si minus 1/2, amindoua solutiile sint valabile)

3x^2=75, we divide by 3, we get x^2=25, x=+&-5

49x^2=121 , x=+and- 11/7

25x^2=225 divide by 25, x^2=9, x =+and - 3

36x^2=144 we divide by 36, we get x^2=4, x = +and- 2

x^2-0.25=0  x^2=0.25, x=+and - 1/2

2x^2-0.32=0 ,  2x^2=0.32, x^2=0.16 ( i divided by 2) , x=+and- 2/5

4x^2=0.04, divide by 4, x^2=0.01, x=+and - 0.1

3x^2=10.8, divide by 3, x^2=3.6, x=+and - 1,89

for the : determinati solutiile ecuatiilor

a) (x-1)^2=49, do the quadratic, you get x=8 and -6

due to the length of this page, i cant explain every step

b) (2x+1)^2=81, you get x= 4 and -5

c)(3x-1)^2=121, do the quadratic, x=- 10/3 and +4

d) 3(x-3)^2=48, we divide by 3 first , (x-3)^2=16,  we get x=7 and -1

e)5(x+2)^2=45 we divide by 5, (x+2)^2=9,  x=+1and -5

f) 7(2x-1)^2=175 we divide by 7 and we have (2x-1)^2=25 x=+3 and -2

Determine x belong to R

a) 1/9 x^2=16, we multiply 9*16=144, x^2=144, x=+and - 12

1/100x^2-1/64=0, or 1/100 x^2=1/64, x=+and - 5/4

1/25 x^2=0.49, x^2=0.49*25=12.25, x=+ and - 7/2

x = 23.78

step-by-step explanation: