Best Answer

x = 2, y = 8

4x + 8y

= 4(2) + 8(8)

= 8 + 64

= 72

Q: If x equals 2 and y equals 8 then 4x plus 8y equals?

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4x + 8y = 20-4x + 2y = -30First add equations 1. & 2. to get:(4x + -4x) + (8y + 2y) = 20 + -30⇒ 10y = -10⇒ y = -1Multiply equation 2. by 4 and subtract it from equation 1:4x + 8y = 20-16x + 8y = -120⇒ (4x - -16x) + (8y - 8y) = 20 - -120⇒ 20x = 140⇒ x = 7Solution x = 7, y = -1Alternatively, to find x, now that y is known to be -1:Substitute y = -1 into equation 1. to give:4x + 8(-1) = 20⇒ 4x -8 = 20⇒ 4x = 28⇒ x = 7The solution can be checked y substituting the values found for x and y in to equation 2. and checking it is the correct value:-4x + 2y = -4(7) + 2(-1)= -28 + -2= -30as required, so the solution is correct.

2y = 4x + 4y = 2x + 2

7 + 8y - 3y + 2 =7 + 2 + 8y - 3y = 9 + 8y - 3y = 9 + 5y

X=2

2x + 2 = 4x -1 2x = 3 x = 1.5

Related questions

(2, 1)

Solve for Y algebraically. 4X + 8Y = 16 8Y = - 4X + 16 Y = - 1/2X + 2 graph and see that the Y intercept = 2

(2xy-4x)+ (8y-16)=2xy-4x+8y-16, which factors as 2(x+4)(y-2)

There is no equation on the list you're showing that has the same graph as [ 4x + 8y = 12 ].

( 2xy - 4x ) + ( 8y - 16)2 ( xy - 2x ) + 2 ( 4y - 8 ) Answer

4x + y = 9 so that y = 9 - 4x 7x - 8y = 6 7x - 8*(9-4x) = 6 7x - 72 + 32x = 6 39x = 78 x = 2 Then y = 9 - 4x = 9-4*2 = 9-8 = 1

4x + 8y = 20-4x + 2y = -30First add equations 1. & 2. to get:(4x + -4x) + (8y + 2y) = 20 + -30⇒ 10y = -10⇒ y = -1Multiply equation 2. by 4 and subtract it from equation 1:4x + 8y = 20-16x + 8y = -120⇒ (4x - -16x) + (8y - 8y) = 20 - -120⇒ 20x = 140⇒ x = 7Solution x = 7, y = -1Alternatively, to find x, now that y is known to be -1:Substitute y = -1 into equation 1. to give:4x + 8(-1) = 20⇒ 4x -8 = 20⇒ 4x = 28⇒ x = 7The solution can be checked y substituting the values found for x and y in to equation 2. and checking it is the correct value:-4x + 2y = -4(7) + 2(-1)= -28 + -2= -30as required, so the solution is correct.

It looks like you have 2 simultaneous equations with 2 variables:4x + 8y = 20 and -4x + 2y = -30. Solution is {x=7, y = -1}.One way to solve:Add the two equations together, combining like terms: (4x - 4x) + (8y + 2y) = 20-30 --> 0 + 10y = -10 --> y = -1. Substitute this into either of the original equations and solve for x=7, then check in the other equation to make sure you calculated correctly.

2xy - 4x + 8y - 16 can be factored.(2xy - 4x) + (8y - 16)2x(y - 2) + 8(y - 2)Since y-2 is the same as the other, it would turn out like this:(2x + 8)(y - 2):]

2

2xy + 4x + 8y + 16 = 2[xy + 2x + 4y + 8] = 2[x(y + 2) + 4(y + 2)] = 2(y + 2)(x + 4)

y = -1