Answer: -5.6
Step-by-step explanation:
Simplifying
(4x + -28) = 9x
Reorder the terms:
(-28 + 4x) = 9x
Remove parenthesis around (-28 + 4x)
-28 + 4x = 9x
Solving
-28 + 4x = 9x
Solving for variable 'x'.
Move all terms containing x to the left, all other terms to the right.
Add '-9x' to each side of the equation.
-28 + 4x + -9x = 9x + -9x
Combine like terms: 4x + -9x = -5x
-28 + -5x = 9x + -9x
Combine like terms: 9x + -9x = 0
-28 + -5x = 0
Add '28' to each side of the equation.
-28 + 28 + -5x = 0 + 28
Combine like terms: -28 + 28 = 0
0 + -5x = 0 + 28
-5x = 0 + 28
Combine like terms: 0 + 28 = 28
-5x = 28
Divide each side by '-5'.
x = -5.6
Simplifying
x = -5.6
Answer:
13
Step-by-step explanation:
it's a 5,12,13 triangle
and we can find the sides by Pythagorean theorem:
a^2 + b^2 = root of c
25 + 144 = 169
root of 169 = 13
Answer:
3
Step-by-step explanation:
3.5*4.5=15.75 ft^2
15.75/5.25=3 bags
Answer:
405
Step-by-step explanation:
To find sample size, use the following equation, where n = sample size, za/2 = the critical value, p = probability of success, q = probability of failure, and E = margin of error.

The values that are given are p = 0.84 and E = 0.03.
You can solve for the critical value which is equal to the z-score of (1 - confidence level)/2. Use the calculator function of invNorm to find the z-score. The value will given with a negative sign, but you can ignore that.
(1 - 0.9) = 0.1/2 = 0.05
invNorm(0.05, 0, 1) = 1.645
You can also solve for q which is 1 - p. For this problem q = 1 - 0.84 = 0.16
Plug the values into the equation and solve for n.

Round up to the next number, giving you 405.