Ateacher had 21 red pens. if the ratio of red pens to blue pens she owned 3: 1, how many pens did she have total?

These question are hard can you me with answers

Marco has $38.43 dollars in his checking account. his checking account is linked to his amazon music account so he can buy music. the songs he purchases cost $1.29. part 1: write an expression to describe the amount of money in his checking account in relationship to the number of songs he purchases. part 2: describe what the variable represents in this situation.

Which expression and diagram represent “renee biked four times as far this month as last month”?