Best Answer

Your answer is x = 1 & y = -2

Given Equations:

2x-y=4

y=5x-7

Using Substitution

Substitute y for 5x-7 to simplify the equation to only 1 variable.

2x-(5x-7)=4

Simplify

a. 2x-5x+7=4

b. -3x=-3

c. x=1

Solve for y

Plug your x into the y equation

y=5*(1)-7

y=-2

Check your answers

Plug your variables into the multi-varible equation

2*(1)-(-2) = 4

Q: 2x-y equals 4 and y equals 5x-7?

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2xy=2*30*2=120

No, it equals -2xy. lrn2math

Y=15/(2c+2x)

2xy*9 if x=3 and y = 2 2(3)(2)*9 12*9 108 You substitute x and y for their equivalent (3 and 2) then simply multiply 2*x*y, then multiply the answer of that by 9.

x2 + y2 = x2 - 2xy + y2 + 2xy = (x - y)2 + 2xy = 72 + 2*8 = 49 + 16 = 65 You could, instead, solve the two equations for x and y and substitute, but the above method is simpler.

Related questions

2xy substitute 3 for y and 5 for x 2(5)(3) = 30

2xy=2*30*2=120

Assuming y' is dy/dx, y = x^4/4 + yx^2

No, it equals -2xy. lrn2math

Because 2x+y is addition not multiplication

Y=15/(2c+2x)

2xy*9 if x=3 and y = 2 2(3)(2)*9 12*9 108 You substitute x and y for their equivalent (3 and 2) then simply multiply 2*x*y, then multiply the answer of that by 9.

x2 + y2 = x2 - 2xy + y2 + 2xy = (x - y)2 + 2xy = 72 + 2*8 = 49 + 16 = 65 You could, instead, solve the two equations for x and y and substitute, but the above method is simpler.

The question doesn't nail it down; i.e., there can be several answers that satisfy the given information. Perimeter 'P' = 2 x (Length + Width) Area 'A' = (Length) x (Width) = 2 x y What is the Length, and what is the Width ? Here are five correct answers: ==> If the rectangle is (2) by (x y), A = 2xy, P = 4 + 2xy ==> If the rectangle is (2x) by (y), A = 2xy, P = 4x + 2y ==> If the rectangle is (x) by (2y), A = 2xy, P = 2x + 4y ==> If the rectangle is (1) by (2xy), A = 2xy, P = 2 + 4xy ==> If the rectangle is (0.1) by (20xy), A = 2xy, P = 0.2 + 40xy

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

4

[ 2xy - 8x ] is. Another way to write it is [ 2x(y - 4) ] .We can't tell what number it is unless we know the values of 'x' and 'y'.