If 4s + t = 2 and 3r -12s = 3, what is the value of r + t?

A) 2


B) 3


C) 5


D) 6


E) 7





2) If 3x-7 = 5, what is the value of 2x-4?


A) 4


B) 5


C) 6


D) 8


e) 12





3) The average (arithmetic mean) of John's and Amy's heights is 64 inches, and the average of John's, Amy's, and Nancy's heights is 65 inches. How tall is Nancy?





A) 64 inches


B) 65 inches


C) 66 inches


D) 67 inches


E) 68 inches

If 4s + t = 2 and 3r -12s = 3, what is the value of r + t?
1)3
Reply:1)B


2)A


3)D


Next time do it yourself lol
Reply:Q1) (B) 3





t=2-4s


3r-12s=3 (to be divisible by 3)


r-4s=1


r=1+4s


so r+t


= 1+4s+2-4s


=3





Q2) (A) 4





3x-7=5


x=(5+7)/3


= 4


so 2x-4


=2(4)-4


=4





Q3) (D) 67





total height for john and amy is


64*2=128


total height for john, amy and Nancy is


65*3=195


therefore, the height for Nancy is


195-128=67
Reply:1.


4s + t = 2


3r - 12s = 3





divide the second equation by 3


r - 4s = 1


add this to the first equation


4s + t = 2


r - 4s = 1


----------------


r + t = 3


B





2.


3x - 7 = 5


solve for x


3x = 7 + 5


3x = 12


divide both sides by 3


x = 4





substitute the value of x


2x - 4


2(4) - 4


8 - 4


4





A.





3.


let x be the height of John, y be the height of Amy and z be the height of Nancy





x + y


------- = 64 (equation 1)


2





x + y + z


----------- = 65 (equation 2)


3





multiply the equation 2 by 3


x + y + z = 195


x + y = 195 - z


divide both sides by 2


x + y


------ = (195 - z)/2


2





since equation 1 tells that (x + y)/2 = 64 substitute it





64 = (195 - z)/2


128 = 195 - z


z = 195 - 128


z = 67





Nancy is 65 inches tall


D