*The straight line, L1, has an equation y= -2x+5

Question

1.) Write down the gradient of L1
2.) Line 2, is perpendicular to L1, and passes through the point (4,5).
a. Write down the gradient of L2
b. Find the equation of L2.
3.) Line 2, is perpendicular to L1, and passes through the point (4,5). Write down the coordinatesof the point of intersection of L1 and L2.

Answer 1

gradient = slope
y=mx+b is called the slope-intercept for a reason

perpendicular lines have slopes whose product is -1
so, your new line has slope -1/m and its equation in point-slope form is
y-5 = -1/m (x-4)

Now work your magic. Come back with what you have if you get stuck.
But first, review the topic some more ...