You have to make a system of equations: lets make a equal the amount marry makes per student and b be her base amount.
90=15a+b (you have to subtract the top equation by the bottom equation)
62=8a+b (90-62=28, 15a-8a=7a, and b-b=0)
Since b canceled out, you are left with 7a=28 which means a=4. you can than plug a into the equation 62=8a+b to find that b=30.
since Lisa makes half of the base amount marry, her base amount is 15. However, she also make twice the amount per kid so she makes 8 per kid.
using the found values found you can make the equations (m=the amount Marry makes, l=the amount Lisa makes, and c is the number of children)
m=4c+30
l=8c+15
set c=20 and you should get m=110 and l=175. Based off of that information, we can say that Lisa makes more money instructing a class of 20 students.
I hope this helps.
Answer:
He burnt 1000 calories per hour when playing basketball.
Step-by-step explanation:
Let B be calories burned playing basketball, and C calories burned canoing.
1800 = B + 2C
3200 = 2B + 3C
From 1st equatipn, we get that B = 1800 - 2C
Replacing into the 2nd equation, we have:
3200 = 2(1800-2C) + 3C
3200 = 3600 - 4C + 3C
3200 = 3600 - 1C
C = 3600 - 3200
C = 400
Knowing C, we find B.
B = 1800 - 2C = 1800 - 2*400 = 1800 - 800 = 1000 calories.
He ate 1 - 6/8 which is 2/8, or 1/4 of an orange.
(9x+10)² or (9x+10)(9x+10)
Water was pumped out in t-hours.
Time t would be the domain, 0 to t.