A textbook store sold a combined total of 209 history and math textbooks in a week. The number of math textbooks sold was 75 less than the
number of history textbooks sold. How many textbooks of each type
were sold?

67 math, 142 history

Step-by-step explanation:

lets say the number of math textbooks was x and the number of history textbooks is y. we have x+y=209 and x=y-75. we can plug the second equation into the first to get y-75+y=209. simplfy to get 2y=284 so y=142. since x=y-75, x=67

step-by-step explanation:

always plug in x. in this case, x equals 4.

i'm going to first solve 4(2+3x)

1) 4(2+3(4)) use pemdas to solve.

i'm going to multiply whats in the parenthesis first, so 3 times 4=12.

2)4 (2+12) i'm then going to multiply 4 by both numbers in the parenthesis (because multiplying comes before adding)

4 times 2= 8.   4 times 12= 48

4) (8+48)= 56 (answer)

i'm then going to solve 8+12x and plug in 4 for x.

1) 8 +12(4)

multiplying comes before adding, so i'm gonna multiply 12 and 4.

12 times 4= 48.

2) 8+48=56

both equal the same!