He gave away 9 (20 x (3/7) =9) so 21-9=12
Answer:
Step-by-step explanation:
Assuming that for each option, you play the same number of games,x
Let y represent the cost of playing x games using option A
Option A is to buy a membership card and pay $2 every time you go to the gym. The membership card costs $20. It means that
y = 20 + 2x
Let z represent the cost of playing x games using option B
Option B is to pay $4 each time you go. It means that
z = 4x
To determine how many games will be played before cost of option A equal to the cost of option B, we would equate y to z. It becomes
20 + 2x = 4x
4x - 2x = 20
2x = 20
x = 20/2 = 10
It will take 10 games for both to be the same
Answer:
x = 15
Step-by-step explanation:
The two angles form a straight line so they add to 180 degrees
3+6x + 5x+12 = 180
Combine like terms
11x+15 = 180
Subtract 15 from each side
11x+15-15 =180-15
11x = 165
Divide by 11
11x/11 =165/11
x =15
Answer:
13.5
Step-by-step explanation:
72/(16/3)
First convert the equation in the form of <em>y= mx + </em><em>c</em>
The equation will be like = y = 6x-5
value of m = 6
The slope of perpendicular line will be = -1/m = -1/6