X = -3y+6 2x+8y= -12

i cannot solve this equation but it needs to be solved by substitution.

Since x= -3y + 6

Substitute this into equation 2

You now have equation 2 as

2(-3y+6) + 8y = -12

-6y + 12 + 8y = -12

8y - 6y = -12 -12

2y = -24

y= -12

x = -3(-12) + 6

x= 36 + 6

x= 42.

x + 3y = 6

2x + 8y = -12

substracting first equation from the second will give us

x - 5y = -18

subtracting the first one from this will give us

-8y = -24

y = 3

x = -3

since your problem is x^4 = 81, what you have to undeo is the "to the fourth power" part.

the inverse (opposite operation) of "to the fourth power" is "to the fourth root".

  (x^4) ^ ¼   = 81 ^ ¼  

  81 = 3^4     so (3 ^ 4) ^ ¼   =   3 ^ 1   = 3

by hand: (3 ^ 4) ^ ¼   =   3 ^ (4 x ¼) = 3 ^ 1   = 3   (when you take a power to a power, multiply the exponents.)

or, do it by calculator. one way of finding the fourth root is to use ^ (1/4)

step-by-step explanation:

step-by-step explanation: