Best Answer

This is a simultaneous equation question.

4(3x+4y = 90)

3(4x-3y = -5)

Multiply the top equation by 4 and the bottom equation by 3 then subtract the bottom equation from the top equation remembering that in maths a minus from a minus is equal to a plus.

12x+16y = 360

12x-9y = -15

And when subtracted:

0+25y = 375

Divide both sides of the equation by 25 to find the value of y:

y = 15

Substitute 15 for y into the original equation to find the value of x:

Solution: x = 10 and y = 15

Q: 3x plus 4y equals 90 4x-3y equals -5?

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It is: 3x+4y which is an algebraic expression

y = 3x 3x + 4y = 30 3x + 4(3x) = 30 3x + 12x = 30 15x = 30 x = 2 y = 3x y = 3(2) y = 6 (2, 6)

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3x - 4y = 8Solve for x:3x = 4y + 8x = 4/3y + 8/3Solve for y:-4y = -3x + 8y = 3/4x - 2

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(2, -1)

2x + 3y = 17 3x + 4y = 24 (2x + 3x) + (3y + 4y) = (17 + 24) 5x + 7y = 41

4y = 3x+11 or as y = 3/4x+11/4

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(-1, 5)

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It is:- 3x+4y = 8 4y = -3x+8 y = -0.75x+2 So the slope is -0.75 and the y intercept is 2

Yes.

It is: 3x+4y which is an algebraic expression

3x + 4y = 12 Subtract 3x from each side 4y = 12 - 3x Divide by 4 on each side y = 3 - .75x The slope is what is multiplied by "x" or -.75

3x=4y-x 4x=4y x=y