Answer: He made $90 last week.
Assumption :
Let, Luis made $X last week.
He made $72 this week which is 80% of $X that he made last week
⇒ X * 80% = 72
⇒ X * 80/100 = 72
⇒ X = (72 * 100)/80
⇒ X = 90
Therefore, he made $90 last week.
To remember :
While solving this type of problems, be careful to understand which one of last time and current time is not given; just assume that one and input other conditions, the problem will be solved.
15%=3
5%=1
5(20)=100
1(20)=20
So, there are 20 students in the class.
Answer:
3/4
Step-by-step explanation:
3x - 4y = 7.....subtract 3x from both sides
-4y = -3x + 7 ...now we divide both sides by -4
(-4/-4)y = (-3/-4)x + (-7/4)...simplify
y = 3/4x - 7/4
y = mx + b
y = 3/4x - 7/4.....so the number in the m position is 3/4 <== ur slope