Answer:
D) 8x - 1
Step-by-step explanation:
Let's say that x = 5. That would mean Amelia put 15(5) - 4 gallons of gas in her car, which equals 71 gallons. She used 7(5) - 3 gallons driving to work, which is 32 gallons used. 71 - 32 = 39 gallons left.
What else equals 39, you might ask?
8(5) - 1
40 - 1
39.
Answer:
x=2, y=1
Step-by-step explanation:
2x + y = 5
5x − 2y = 8.
Multiply the first equation by 2
2( 2x + y) = 5*2
4x +2y = 10
Add this to the 2nd equation to eliminate y
4x+2y = 10
5x -2y = 8
--------------------
9x = 18
Divide by 9
9x/9 = 18/9
x = 2
Now find y
2x+y = 5
2(2)+y = 5
4+y = 5
Subtract 4 from each side
y = 5-4
y =1
SA , 4 and pi are all constants so you can ignore them.
* edit: had r and h reversed..
1 = (3h)(r)^2
1/3 = h(r)^2
1/3 = (r)^2
√(1/3) = r
h and r are inversely related so tripling h will reduce r by 1/√(3)
Answer:
35 boys
(and 50 girls)
Step-by-step explanation:
If b is the number of boys, then the number of girls is b+15
So the sum is b+b+15 = 85
So 2b = 85-15 = 70, so b=70/2=35