The length of Joe's arm is 28 inches. The length of his lower arm is 21 inches. What percent of Joe's arm is his lower arm?

75%

Step-by-step explanation:

You take the length of the lower arm, 21, and divide it by the total length, 28. Your equation should be 21/28 = 3/4 =.75. 0.75 is equal to 75%

5=812a+9+3

step 1: simplify both sides of the equation.

5=812a+9+3

5=(812a)+(9+3)(combine like terms)

5=812a+12

5=812a+12

step 2: flip the equation.

812a+12=5

step 3: subtract 12 from both sides.

812a+12−12=5−12

812a=−7

step 4: divide both sides by 812.

812a /812 = -7/812

a= -1/116

so the answer is

a=   -1/116