Serena wants to solve the following system of equations in the most efficient way.

2 x + 3 y = 18. x + 7 y = 31.

She plans to solve for x in the first equation as her first step since both 2 and 3 can be divided into 18. Why is Serina mistaken? Serina should have solved for x in the second equation because it has a coefficient of 1. Serina should have solved for y in the first equation because dividing by 3 instead of by 2 would give a smaller number in the solution. Serina should have solved for y in the second equation because it has the largest coefficient. Serina should have solved for y in the first equation because the division step will be easier since 18 is divisible by 3.

Serina should have solved for x in the second equation because it has a coefficient of 1.

Step-by-step explanation:

we have

----> equation A

---> equation B

we know that

To solve the system of equations in the most efficient way, solve for x equation B and then substitute the value of x in equation A

so

----> equation C

substitute equation C in equation A

solve for y

Find the  value of x

substitute the value of y in the equation C

The solution is (3,4)

therefore

Serina should have solved for x in the second equation because it has a coefficient of 1.

answer: on graphs, the open and closed circles, or vertical asymptotes drawn as dashed lines us identify discontinuities.

as before, graphs and tables allow us to estimate at best.

when working with formulas, getting zero in the denominator indicates a point of discontinuity.

when working with piecewise-defined functions, check for discontinuities at the transition points where one piece ends and the next begins.

step-by-step explanation: