Answer:
Jeff mows 9 yards of lawn in 30 minutes
Step-by-step explanation:
The equation that models the amount of time (t) in minutes it takes Jeff to mow an average sized yard is
, where n is the number of yards he mows.
To find the number of yards Jeff mows in 30 minutes, we set the equation to 30 and solve for n.

Add -12 to both sides:


Divide both sides by 2


Hence Jeff mows 9 yards of lawn in 30 minutes.
Answer:
x=45
Step-by-step explanation:
An entire triangle is 180 degrees and you already know that one angle is 90 degrees. 180 - 90 is 90. Now you have the equation 2x=90.
You then divide each side by 2 to get the x by itself which leaves you with x=45.
A "system" of equations is a set or collection of equations that you deal with all together at once. Linear equations (ones that graph as straight lines) are simpler than non-linear equations, and the simplest linear system is one with two equations and two variables.