Y = ax + b;
0.89 = a * 2 + b and 2.09 = a * 5 + b =>
=> 2.09 - 0.89 = a * 5 + a * 2 + b - b => 1.20 = 3 * a => a = 1.20 / 3 => a = 0.40;
b = 0.89 - 0.40 * 2 => b = 0.89 - 0.80 => b = 0.09;
y = 0.40x + 0.09 => 0.40x - y + 0.09 = 0 is the linear equation.
Answer: B) 4 & 1/6
Nice work on getting the correct answer.
============================================================
Explanation:
x is opposite the marked acute angle
5 is opposite the corresponding acute angle
So x and 5 are proportional to each other. We can form the ratio x/5
Similarly, 10 and 12 are proportional to one another. We can form the ratio 10/12.
Set those ratios equal to each other and solve for x
x/5 = 10/12
12x = 5*10 ... cross multiply
12x = 50
x = 50/12 ...... divide both sides by 12
x = (25*2)/(6*2)
x = 25/6
x = (24+1)/6
x = 24/6 + 1/6
x = 4 + 1/6
x = 4 & 1/6 which shows why <u>choice B</u> is the answer.
Side note: 25/6 = 4.167 approximately
You said there were 40 yellow carsso 40×9 is 360
Divide total bought by 3 and multiply by 20cents:
210/3 = 70
70 x 0.20 = $14.00
Subtract the amount they paid by the amount they made:
14.00 - 6.50 = $7.50
The profit made was: $7.50
