Linear Equations

Question 1

standard form

Answer 1

y = mx + c

Question 2

gradient from graph (m)

Answer 2

m = y2 - y1/ x2 - x1

Question 3

equation of a line

Answer 3

y - (y1) = m(x - (x1))
*don’t necessarily need both points of each

Question 4

horizontal line

Answer 4

y = #

Question 5

vertical line

Answer 5

x = #

Question 6

goes through origin

Answer 6

y = mx

Question 7

gradient of two points graph (m)

Answer 7

m = y2 - y1/ x2 - x1

Question 8

length of line segment

Answer 8

d = √(x2 - x1) + (y2 - y1)

Question 9

midpoint line segment (M)

Answer 9

M = (x1 + x2/2, y1 + y2/2)

Question 10

parallel lines

Answer 10

same gradient
*need to put in standard form

Question 11

perpendicular lines

Answer 11

negative reciprical
Mperp = -1/Mogr

Question 12

simultaneous equations by elimination

Answer 12

1. make same coefficients
2. make different signs
3. add equations together
4. sub in x/y to find x/y
   *On case use solve function

Question 13

simultaneous equations by substitution

Answer 13

1. substitute y=/x= equations into other pair
2. sub x/y to find x/y
   *On case use solve function

Question 14

showing that points lie on the line

Answer 14

1. find LHS and RHS of equation
2. If they are the same, it lies on the line

Question 15

sketching graph

Answer 15

must need:
1. two labelled points
2. equation of line (as it is in in the question)