If there are 40 children aged twelve and under and x of them are under three years old, 40 - x aged three twelve years old. From the 92 people that where taken by the company on whale watching trips, 52 are over twelve years old. The equation that best show the total cost, C is
(40 - x)(36) + (52)(48) = C
Rearranging the equation gives,
x = 40 - ((C - 2496)/ 36)
Step 1:
x² + 4x = 192
Step 2:
Take x common:
x ( x + 4) = 192
Length is x and width is x+4
Step 3:
x² + 4x - 192 = 0
Step 4:
x² + 16x - 12x - 192 = 0
x(x+16) - 12(x+16) = 0
(x-12)(x+16) = 0
⇒ x=12, x=-16
Because the length can't be -16, the length is 12.
If you substitute the values x = 0 and y = −5 into the second equation, you get a false statement: 2(−5) − 10 = 2(0). To solve this system, try rewriting the first equation as x = 2y − 8. Then substitute 2y − 8 in for x in the second equation, and solve for y. The correct answer is x = −2, y = 3.
