Stage 8 - Q1 - 2 marks
Find y when \(x=3\) in \(y=2x+4\).
Hint
Multiply before adding.
Stage 8 - Q2 - 2 marks
Find y when \(x=-2\) in \(y=3x-1\).
Hint
A positive times a negative is negative.
Stage 8 - Q3 - 4 marks
Complete the table, then plot the straight line on the grid.
Hint
Complete all values before plotting.
Stage 8 - Q4 - 4 marks
Complete the table, then plot the straight line on the grid.
Hint
The y-intercept is the value at \(x=0\).
Stage 8 - Q5 - 2 marks
Check whether \(\left(5,\ 19\right)\) lies on \(y=4x-1\).
Hint
A point lies on a line only if its coordinates satisfy the equation.
Stage 8 - Q6 - 2 marks
Find a so that \(\left(a,\ 17\right)\) lies on \(y=3x+2\).
Hint
Use the y-coordinate as the output.
Stage 8 - Q7 - 3 marks
A table for \(y=5x-2\) contains points \(\left(-1,\ -7\right)\), \(\left(0,\ -2\right)\), \(\left(2,\ 7\right)\). Identify and correct the error.
Hint
Two correct points do not guarantee every table entry is correct.
Stage 8 - Q8 - 3 marks
For \(y=2x+3\), find the x- and y-intercepts, then explain why they are different numbers.
Hint
Use zero for the coordinate belonging to the other axis.
Stage 8 - Q9 - 4 marks
The line \(y=4x+1\) is plotted only for \(-2\le x\le 2\). Is \(\left(7,\ 29\right)\) on the mathematical line? Explain the difference between a graph window and a restricted domain.
Hint
Ask whether the problem restricts the function or merely the drawing.
Stage 8 - Q10 - 5 marks
Challenge: a straight line contains \(\left(2,\ 7\right)\) and \(\left(5,\ 16\right)\). Find its equation, predict y at \(x=1.5\), and test whether \(\left(8,\ 25\right)\) is on it.
Hint
Use the change between the two points, then substitute one point.