Yusuf tried to solve an equation step by step.
1/4r+2=10
1/4R=12 step 1
r=48 step 2
Find Yusuf’s mistake

If a • b*2 = 1.8 x 10*-7, and c•b/d = 7.2 x 10*-4, find the value of a•d*2/c*2

Me d is also an option but i couldn't get it in the picture

Afamily has two cars. the first car has a fuel efficiency of 25 miles per gallon of gas and the second has a fuel efficiency of 15 miles per gallon of gas. during one particular week, the two cars went a combined total of 1025 miles, for a total gas consumption of 55 gallons. how many gallons were consumed by each of the two cars that week?