Simply, the question is this: What is the range of y = [x + 2]? It's a step function that is to be rounded down. The correct answer was apparently all multiple of 4, but wouldn't it be all integers? Since if I input x as -2 then wouldn't y come to equal 0, given that -2 + 2 would be 0 then multiplied by 4 gives y as 0. 0 wouldn't be a multiple of 4, so can someone explain to me where I went wrong?

answer: give more info

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