I think it's :
Part A ; $30 * (x) + $13
$28 * (x) + $15
Part B ; so $30 * 4 + $13 = $133 vs.
$28 * 4 + $15 = $111 so that would mean company B Would charge the least amount.
Part C ; the difference between company a and company B prices is $22.
3t+1
The t stands for tent, and is being multiplied by 3 because there is always going to be 1 tent for every 3 campers. Plus one, for the camp leader.
Slope intercept form : y = mx + b
4x - 5y < 1
-5y < -4x + 1
y > 4/5x - 1/5 <== slope intercept form
y - x > 3
y > x + 3 <== slope intercept form
Your total after tax is $30.12
A 20% tip is approximately $5.50 ($5.67)
If I'm correct the answer would be C.) hope this help