If two linear equations, y = x + 4 and y = 2x + c, intersect at x = 1, find c.
Draw the two equations, indicating the point of intersections (whiteboard).If the lines intersect at x=1, then at that point the y values of each equation are equivalent. Therefore, x+ 4 = 2x + c.Inputting x=1, (1)+4 = 2(1) + c, which is the same as 5 = 2 + cThe answer follows as c = 3.
TD
Related Maths GCSE answers
All answers ▸How do I use Pythagoras to work out the length of a triangle?
Draw a graph of x = (y+4)/4.
Find the area of a kite with length 12cm and height 6cm.
Write x² + 4x -16 = 0 in the form (x+a)² - b = 0. Solve the equation giving your answer in surd form as simply as possible.