Solve for y in the first equation x + 3y = 6 2x − y = 10

Solve equation [1] for the variable x [1] x=(3y+6)

Plug this in or variable x in equation [2]

[2] 2(-3y+6)-y= 10

[2] -7y=-2  

// solve equation [2] for the variable y

[2]   7y= 2

[2]    y=2/7

By now we know this much  

X= -3y+6

Y=2/7

Use the y value to solve for x  

X=-3(2/7)+6=36/7

(x,y)=(36,7), (2/7)  

problem:

f(x) = - 2/3x + 5; f(5/2)

substitute 5/2 in for x:

f(5/2) = -2/3(5/2) + 5

simplify the right side:

f(5/2) = -5/3 + 5

f(5/2) = 10/3

f(5/2) = 10/3

i hope this !

12

step-by-step explanation:

a triangle's   full angle is 180 degrees so 180 - 156 = 24. 24/2=12