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on a math test, jun was asked to find the point(s) where the equations y = x2 + 10x – 6 & y = 7x – 2 intersect.

jun’s solution is shown below.

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
the graphs intersect at (-4, 0) and (1, 0)

a) is jun’s solution correct? explain why or why not.
b) if jun’s solution is incorrect, show the correct work for this problem.

(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 to this point, but she didn't go far enough. 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).

$450

step-by-step explanation:

first, you have to multiply 150x2=300

next, you have to add 150+300= 450

answer: 20

step-by-step explanation: