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(2x + 3y)^2 – (2x – 3y)^2 = 360 show that xy is a multiple of 5

Expand first brackets: 4x 2 +6xy+6xy+9y 2 Expand second brackets: 4xy 2 -6xy-6xy+9y 2 Subtract the second expansion from the first one, being careful of the double negative: =24xy Then, back into the origina...
RM
Answered by Ryan M. Maths tutor
10302 Views

Solve the simultaneous equations 5x + 3y = 24 and 3x - 4y = 26

Ok, so here are the equations5x+3y=243x-4y=26So let's multiply the first equation by 3, which gives us:15x+9y=72Now let's multiply the second equation by 5, which gives us:15x-20y=130So we're now left with:1...
WS
Answered by William S. Maths tutor
12197 Views

How do I solve x^2+6x+8=0?

Ok, so we would call this a quadratic equation because it is written in the form of ax^2+bx+c=0 (in our case, a=1, b=6, c=8).Luckily, this type of quadratic equation can be factorised, so we can solve it eas...
WS
Answered by William S. Maths tutor
17908 Views

Solve the simultaneous equations y = 2x-3 and x^2 +y^2 = 2

Let the first equation be equation 1 and the second equation be equation 2. Firstly, you must substitute equation 1 into equation 2. This is because there are currently two unknown values in each equation (x...
DD
Answered by Daniel D. Maths tutor
30621 Views

Solve for x: 2x^2 + 7x + 6 = 0

Solve for x: 2x 2 + 7x + 6 = 0 The first thing to do is look at the left hand side and factorise it. To do this we use the reverse of FOIL. Then when the expression is factorised, we can solve for x. 1. Firs...
AC
Answered by Asher C. Maths tutor
20192 Views