Where do the lines 2y = 4x + 2 and - 3x + y = 4 intersect?

Rearrange the second equation in the form y = mx + c to get y = 3x + 4. Divide the first equation by 2 to get y = 2x + 1. When the lines intersect, they'll have the same x and y values, hence, set the equations equal to each other to find the x co-ordinate: 2x + 1 = 3x + 4. Collecting like terms gives 1 = x + 4, and then taking the 4 to the other side of the equation gives x = -3. This value is substituted into either equation, allowing you to find the y co-ordinate: (using equation 1) y = 2(-3) + 1, which gives y = -5. Therefore, the two lines intersect at the point (-3,-5).

EJ

Related Maths GCSE answers

All answers ▸

How can you factorise x^2-9


The perimeter of a right-angled triangle is 72 cm. The lengths of its sides are in the ratio 3 : 4 : 5. Work out the area of the triangle.


Solve the quadratic equation x^2 + 3x + 2 = 0, by factorisation.


How do you find the maximum and minimum value of a quadratic function with no use of calculus?