4x-4y=0
y=2x+6
solve by substitution

x = -6, and y = -6  (-6, -6)

Step-by-step explanation: What we have here is a pair of simultaneous equations. Since we have been instructed to solve by substitution, we shall begin with the one which has one of the variables as having a coefficient of 1. We shall start with equation 2 which is,

y = 2x + 6

Having taken note of this, we can now go on to the other equation and substitute for the value of y.

Hence, from equation 1,

4x - 4y = 0 (substitute for the value of y)

4x - 4(2x + 6) = 0

4x - 8x - 24 = 0

-4x -24 = 0

Add 24 to both sides of the equation

-4x = 24

Divide both sides of the equation by -4

x = -6

Having calculated the value of x, we can now go on to substitute for the value of x in equation 2.

Therefore,

y = 2x + 6

y = 2(-6) + 6

y = -12 + 6

y = -6.

So, x = -6 and y = -6

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step-by-step explanation:

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3x + 18 = 147°

step-by-step explanation:

3x + 18 = 147°, because the value of the central angle is equal to the value of the arc formed by it.

i hope i you.