3² = -1*3² = -1 * 9 = -9 (order of operations) while (-3)² = (-) = +9 or 9

evaluate: z2 – x2 -xy if x = -2, y = 3, and z = -4 ( see section 1.8 for further review)

  20

Step-by-step explanation:

Assuming your question is:

Z² - X² - XY     X = -2, Y = 3, Z = -4

Substitute values

(-4)² - (-2)² - {(-2)(3)}

{(-4)(-4)} - {(-2)(-2)} - (-6)

(16) - (4) + 6

16 - 4 + 6

20

x > 1.3

step by step:

8.5−0.9x> 9.8−1.9x

step 1: simplify both sides of the inequality.

−0.9x+8.5> −1.9x+9.8

step 2: add 1.9x to both sides.

−0.9x+8.5+1.9x> −1.9x+9.8+1.9x

1x+8.5> 9.8

step 3: subtract 8.5 from both sides.

1x+8.5−8.5> 9.8−8.5

1x> 1.3

step 4: divide both sides by 1.

1x/1 > 1.3/1