Alice spent 6 minutes on each factoring problem and 3 minutes on each evaluation problem. she spent a total of 42 minutes on 9 problems. how many minutes did she spend on factoring?

Let
x> number of factoring problem
y> number of  evaluation problem

we know that
x+y=9> multiply by -6> -6x-6y=-54> equation 1
6x+3y=42> equation 2

adds equation 1 and equation 2

-6x-6y=-54
 6x+3y=42

   -6y+3y=-54+42> -3y=-12> y=4
x+y=9> x=9-y> x=9-4> x=5

she spend on factoring> 6x> 6*5> 30 minutes

the answer is
30 minutes

The distance from point a to point c across the coordinate plane is aproxamatly 8.94 rounded to the nearest hundredth. you use a^2 + b^2 =c^2