Hello!

3x + 5 = x - 10
Solve for x by isolating the variable.
Subtract 5 from both sides:
3x + 5 - 5 = x - 10 - 5
3x = x - 15
Subtract x from both sides:
3x - x = x - x - 15
2x = -15
Divide both sides by 2:
2x /2 = -15 / 2
x = -15/2.
Average of 4 numbers, if the numbers are x,y,z,t then the average is (x+y+z+t)/4=average so
average=98
if 3 of the numbers are 86, 87 and 91 then what is the fourth number
assign
x=86
y=87
z=unknown
91=t
(86+87+z+91)/4=98
do parenthasees first
(264+z)/4=98
multiply both sides by 4 to get rid of fraciton
264+z=392
subtract 264 from both sides
z=128
the fourth number=128
Answer:
the answer is C. how you got 24
Step-by-step explanation:
so find the square of 2 first and that would give -8
-8*4 is -32