X+y=70
x=2y-5
x=larger number
y=smaller number
now plug in the value of x to only have one variable in the equation...
Way to solve for y:
(2y-5)+y=70
3y-5=70
add 5 on both sides...
3y=75
divide by 3 on both sides
y=25
1st way to solve for x:
now plug in y in the original equation...
x+25=70
subtract 25 on both sides...
x=45
2nd way to solve for x:
plug in y for the second equation...
x=25(2)-5
x=50-5
x=45
answer: the two numbers are 45 and 25.
A
x X x
= x^2
B
20 x 20 = 40
C
100 / 40 = 2.5 per square inch
For the average to be 90,
(99 + 93 + x) / 3 = 90
or 192 + x = 270
or x = 270 - 192 = 78
Jim must score at least 78 in the third test.
2
3
2
4
I hope this helps!
Extended response is in order