Solving Equations In Exercises 2140 solve the equation if po

Solving Equations In Exercises 21-40, solve the equation (if possible). (if passible). ** 21-40, solve the equation Geometry The figure shows three squares. The perimeter of square I is 20 inches and the perimeter of square II is 32 inches. Find the area of square III. Forestry A forester mixes gasoline and oil to make 1 2 gallons of mixture for a two-cyclic chainsaw engine. This mixture is 32 parts gasoline and 1 part oil. How much gasoline must be added to bring the mixture to 40 parts gasoline and 1 part oil?

Solution

29. ( 100- 4u)/3 = (5u +6)/4 +6

(100 -4u)/3 - (5u +6)/4 =6

{4(100-4u) -3(5u +6) }/12 =6

400 -16u -15u -18 = 6*12

-31u - 382 = 72

-31u = 454

u = -454/31

30   ( 17 +y)/y + (32+y)/y = 100

( 17 +y+32+y)/y = 100

49 +2y = 100y

98y = 49

y = 1/2

31.   (5x-4)/(5x+4) = 2/3

(5x-4)3 = ( 5x+4)2

15x -12 = 10x +8

5x = 20

x=4

32. (10x+3)/(5x +6) = 1/2

2(10x+3) = 5x+6

20x +6 = 5x+6

15x = 0

x =0