Answer:
Step-by-step explanation:
8r + 9 + 7r + 6 = 90
15r + 15 = 90
15r = 75
r = 5
8(5) + 9 = 40 + 9 = 49
7(5) + 6 = 35 + 6 = 41
Answer:
x = 55 or x = 15
Step-by-step explanation:
Solve Absolute Value.
We know that either 1/5x - 7 = 4 or 1/5x - 7 = -4.
1/5x - 7 = 4
1/5x - 7 + 7 = 4 + 7
1/5x = 11
1/5x (5) = 11 (5)
x = 55 (one possibility)
1/5x - 7 = -4
1/5x - 7 + 7 = -4 + 7
1/5x = 3
1/5x (5) = 3 (5)
x = 15 (second possibility)
Answer:

Step-by-step explanation:
The rule to know and follow is:
You can add, subtract, multiply or divide by anything so long as the same thing is done to both sides of the equals sign;
5a + b = 14
If we want to get: "a = ...", then we use the rule to isolate the variable a on one side of the equation;
Firstly, we subtract b from both sides:
5a + b - b = 14 - b
5a = 14 - b
Then, divide both sides by 5:

Answer:
7.5
Step-by-step explanation:
how i figured it is 18-3 is 15
2*7 is 14 so in turn 7.5 *2 is 15 so
z=7.5