Write an equation for each of the following problems and then solve. a number and 15 total 45

x+15=45

  -15 15

    x=30

30+15=45

Equation: x + 15 = 45

Solved: n = 30

Step-by-step explanation:

You can think of this as saying, "A variable plus 15 equals 45"

Now that you have the equation, you can solve for the variable (in this case it's "n"), using the inverse operation.

Step 1: Isolate n by subtracting 15 from both sides of the equation

Recommended: To check your answer, substitute the result you got for "n" into the original equation:

step-by-step explanation:

x = ±sqrt(10)

step-by-step explanation:

5 - 2x² = -15

subtract 5 from each side

5-5 - 2x² = -15-5

-2x^2   = -20

divide by -2 on each side

-2x^2   /-2= -20/-2

x^2 =10

take the square root on each side

sqrt(x^2 )=±sqrt(10)

x = ±sqrt(10)

check:

5 - 2x² = -15

+sqrt(10)

5 - 2(sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15

-sqrt(10)

5 - 2(-sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15