Answer:
D) y=5x+20
Step-by-step explanation:
Since Irina can paint 1 room in 9 hours, that means she paints 1/9 of the room in 1 hour. Her portion of the equation would be 1/9x, with x being the number of hours she works and 1/9 of a room per hour being her speed.
Since Paulo can paint 1 room in 8 hours, that means he paints 1/8 of the room in 1 hour. His portion of the equation would be 1/8x, with x being the number of hours he works and 1/8 of a room per hour being his speed.
The equation would then be 1/9x + 1/8x = 1 (Irina's portion of the room, plus Paulo's portion of the room, equal to one whole room).
Find a common denominator. 72 is the first number that both 9 and 8 divide evenly into. Since 9*8 = 72, we multiply the top of 1/9 by 8 to convert the fraction and get 8/72x. Since 8*9 = 72, we multiply the top of 1/8 by 9 to convert the fractio and get 9/72x. We now have 8/72x+9/72x=1
17/72x=1
Divide both sides by 17/72:
17/72x ÷ 17/72 = 1÷17/72
x=1/1 ÷ 17/72
x=1/1 * 72/17
x=72/17=4.24
Together it should take them 4.24 hours.
Answer:
x = 11
Step-by-step explanation:
By intersecting chords theorem:

first simplify the numerator (x+3)(x-2)=x^2-2x+3x-6=x^2+x-6
now factor the numerator (x+3)(x-2)
now find the restriction 3x-6=0 3x=6 x=2
now factor the denominator 3(x-2)
((x+3)(x-2))/3(x-2)
now cross off the (x-2)
and you are left with (x+3)/3
ANSWERS:
The restriction is X=2
The simplified fraction is (x+3)/3