One side of the rectangle is x=2, the other side is 2x-5
Add up all the four sides: (x+2) +(x+2)+(2x-5)+(2x-5)=54
6x-6=54
x=10
#3: suppose the first integer is x, then the second one is x+2
x(x+2)=255
x^2 +2x -255 =0
factor the quadratic equation: (x+17)(x-15)=0
x=-17, which is impossible, or x=15
so the two positive integers are 15 and 17
Final result : -3
Step by step solution :Step 1 : 3 - a Simplify ————— 21 Equation at the end of step 1 : (a - 3) (3 - a) ——————— ÷ ——————— 7 21 Step 2 : a - 3 Simplify ————— 7 Equation at the end of step 2 : (a - 3) (3 - a) ——————— ÷ ——————— 7 21 Step 3 : a-3 3-a Divide ——— by ——— 7 21
3.1 Dividing fractions
To divide fractions, write the divison as multiplication by the reciprocal of the divisor :
a - 3 3 - a a - 3 21 ————— ÷ ————— = ————— • ——————— 7 21 7 (3 - a)
3.2 Rewrite (3-a) as (-1) • (a-3) Canceling Out : 3.3 Cancel out (a-3) which now appears on both sides of the fraction line.
Final result : -3
