Step-by-step explanation
Step 1
Let
x represents the number of bills $1
y represents the number of bills $10
Luis has four times as many one-dollar bills as ten-dollar bills,then

Also,his total is still $43,then

Step 2
find x and y , using Equation(1) and (2)
A)replace the value of x, from equation(1) into equation(2)
