2....For this one....I'm using x for a and y for b
So we have
y = 4x + 8
y = -2x +30
Here's the graph : https://www.desmos.com/calculator/25etgvd1ja
2b
-2x + 30 > 12 subtract 30 from both sides
-2x > -18 divide both sides by -2 and reverse the inequality sign
x < 9
Here's the graphical solution : https://www.desmos.com/calculator/wqeiyuxd89
2c.....break even point.....set the functions equal and solve for x
4x + 8 = -2x + 30 add 2x to both sides, subtract 8 from both sides
6x = 22 divide both sides by 6
x = 22/6 = 11/3
And y = 4(11/3) + 8
y = 44/3 + 24/3
y = 68/3
Here's the graph with the break-even point : https://www.desmos.com/calculator/iwcgpjjzqf
2d......we want to solve this
4x + 8 > -2x + 30
6x > 22
x > 22/6
x > 11/3
