x - 2y = -4
2x - y = 1
To solve, multiply both sides of 2nd equation by -2 (remember if you do the same thing to both sides you do not change the equation), then add equations.
x - 2y = -4
-4x + 2y = -2
adding,
-3x = -6
divide by -3 both sides
x = 2
substitute x = 2 into 2nd equation
2(2) - y = 1
4 -y = 1
-y = -3
y = 3
Ans: x = 2, y = 3
2sinx+1 equals 0
1
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
0.3333
4x2 - 4x + 2xy - 2y = 4x(x - 1) + 2y(x - 1) = (x - 1)(4x + 2y) = 2(x - 1)(2x + y)
2xy substitute 3 for y and 5 for x 2(5)(3) = 30
It's an hyperbola equation.
if y = 2- x then x^2 + 2x(2 - x) = 3 ie x^2 + 4 x -2x^2 = 3 ie 4x - 3 = x^2 x^2 - 4x +3 = 0 = (x - 1)(x - 3) so x = 1 or 3 Check: y= 2 - 1 =1; x^2 = 1, 2xy = 2 x 1 x 1 = 2, 1 +2 = 3. y = 2 - 3 = -1; x^2 = 9, 2xy = 2 x 3 x -1 = -6, 9 + -6 = 3. QED.
2sinx+1 equals 0
1
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
0.3333
-(4-3) -(1) -1
a+a=1 2a=1 a=1/2
4x2 - 4x + 2xy - 2y = 4x(x - 1) + 2y(x - 1) (4x + 2y)(x - 1).
x=1
To find the product of 2xy and x, you multiply the coefficients (2 and 1) to get 2, then multiply the variables x and x to get x^2, and finally multiply the variables y and 1 to get y. Therefore, the result of 2xy times x is 2x^2y.