Question 183994
1.Double the sum of a number and 6 is the same as 15 more than triple the same number.
 Find the number
:
Write an equation for what it says, let x = "the number"
2(x+6) = 3x + 15
2x + 12 = 3x + 15
12 - 15 = 3x - 2x
-3 = x
:
check solution in the original statement:
2(-3+6) = 3(-3) + 15
2(3) = -9 + 15
:
:
2.Four less than seven time is the same as nine times the number . Find the number
:
7x - 4 = 9x
7x - 9x = +4
-2x = 4
x = {{{4/(-2)}}}
x = -2
:
Check solution
7(-2) - 4 = 9(-2)
-14 - 4 = -18
:
:
Assume you mean:
3. 8 - x^2; for x = -3
8 - (-3)^2)
8 - (+9)
8 - 9 = -1
:
:
4.-2x^2 - 5z = x= -2 z = -4
-2*(-2)^2 - 5(-4) = 
-2(4) - (-20) =
-8 + 20 = +12