Question: evaluate each expression: 1. 9x + 8y, when x = 4 and y = 5 2. 2x + 8x, when x = 3 3. 4y + 7y, y = 5 4. 10x + 18y, when x = 4 and y = 5 5. x + 8y, when x = 2 and y = 1/4 6. 9x + 8y, when x = 1/3 and y = 1/4 7. 3x + 7y, when x = 8 and y = 4 8. 12x + 16y, when x = 1/4 and y = 5

1.) 9(4) + 8(5)

36 + 40 = 74

2.) 2(3) + 8(3)

6 + 24 = 30

3.) 4(5) + 7(5)

20 + 35 = 55

4.) 10(4) + 18(5)

40 + 90 = 130

5.) 2 + 8(1/4)

2 + 2 = 4

6.) 9(1/3) + 8(1/4)

3 + 2 = 5

7.) 3(8) + 7(4)

24 + 28 = 52

8.) 12(1/4) + 16(5)

4 + 80 = 84

answer: .64

step-by-step explanation

set up the formula for standard deviation for this set of numbers, then simplify