The teacher will be very surprised to see your correct solution 😉

Detail solution

Given the linear equation:

Expand brackets in the left part

Divide both parts of the equation by 3

We get the answer: y = 80/3

y*(300/100) = 720/9

Expand brackets in the left part

y300/100 = 720/9

Divide both parts of the equation by 3

y = 80 / (3)

We get the answer: y = 80/3

Sum and product of roots
[src]

sum

80/3

$$\left(\frac{80}{3}\right)$$

=

80/3

$$\frac{80}{3}$$

product

80/3

$$\left(\frac{80}{3}\right)$$

=

80/3

$$\frac{80}{3}$$

The graph