Answer:
(a) Jun's work was correct as far as it went, but she didn't go far enough.
(b) (1, 5) and (-4, 30)
Step-by-step explanation:
y = x² + 10x – 6
y = 7x – 2
(a) Jun’s solution:
y = x² + 10x – 6
y = 7x – 2
x² + 10x – 6 = 7x – 2
x² + 3x – 4 = 0
(x – 1)(x + 4) = 0
x = 1 or x = -4
Jun's work was correct <em>to this point</em>, but <em>she didn't go far enough</em>. She calculated the x-intercepts of the combined equation, not the values of x and y at which the two equations intersect.
Jun must calculate the value of y that corresponds to each value of x.
(b) The correct solution
Continue Jun's calculations
y = 7x -2 y = 7x - 2
Set x = 1 Set x = -4
y = 7 - 2 y = -28 -2
y = 5 y = -30
The correct solutions are (1, 5) and (-4, 30).
The Figure below shows the graphs of each function with the intersection points at (1, 5) and (-4, 30).