7(x+y)-7x
7x+7y-7x
7y is the answer
The first is proportional the second is proportional and the third is not proportional
2x^2-15=x
2x^2-x-15=0
(X-3)(2x-5)=0
x-3=0 or 2x-5=0
X=3 2x=5
x=5/2=2.5
Answer:
The solution of 
is 64.
Step-by-step explanation:
In Mathematics when two negative numbers are multiplied the result is a positive number, i.e. 
.
The expression to be solved is:
Solve the above expression as follows:
Thus, the solution of is 64.
Answer: Part A = Age, Part B = 154 - 0.7a, Part C = 140 beats per minute (BPM)
Step-by-step explanation: The question states "...in beats per minute, <u>depends on a person's age</u> and can be represented..." and the variable is a, so a is age. To rewrite an expression, you need to multiply the number outside the parentheses with the terms inside the parentheses. In this case 0.7 * 220, which is 154 and 0.7 * a which is 0.7a. So the expression rewritten is 154- 0.7a. In order to solve question C you need to plug in the variable. So 0.7(220 - 20) or 154 - 0.7 * 20, whichever is easier. After solving, your answer will be 140 beats per minute.
