y=8 y = 2x y = 2(4) <-- substitute 4 for x y = 8 <-- this is your answer
13 ? 15
18
x = 3 y = 4 2x + y - 1 = (6) + (4) - 1 = 9
y=|x|/4 The range is [0 , ∞ )
The value is 1 if (x, y) = (4, 3) and 0 otherwise.
y=8 y = 2x y = 2(4) <-- substitute 4 for x y = 8 <-- this is your answer
13 ? 15
x equals 7
x+ySince x=4, we can replace the x with a 4:4+ySince y=12, we can replace the y with a 124+12 = 16
18
x = 8y = -42x - y = 2(8) - (-4) = 16 + 4 = 20
x = 3 y = 4 2x + y - 1 = (6) + (4) - 1 = 9
y=|x|/4 The range is [0 , ∞ )
2x+y = 10 x +y = 4 Subtract bottom equation from top equation: x = 6 Substitute the value of x into the equations to find the value of y: x = 6 and y = -2
y = 2x+5 x+y = 4 Substitute the value of y into the second equation: x+2x+5 = 4 x+2x = 4-5 3x = -1 Divide both sides by 3 to find the value of x: x = -1/3 Substitute the value of x into the original equations to find the value of y: x = -1/3 and y = 4 and 1/3
x = -1/3 and y = 7/12