First set up your two equations:
x + y = 90
x = 2y - 30
Then substitute what x equals in the second equation into the first equation:
(2y -30) + y = 90
Now solve for y:
3y -30 = 90
3y = 120
y = 40
Then use y = 40 and substitute the value for y into one of your original equations and solve for x. I'll choose the first one, but either one will work.
x+ 40 = 90
x = 50
So your solution is x = 50 and y = 40
Step-by-step explanation:
<span>Anna learns in her science class that the human eye blinks an average of 4,200,000 times a year. What is this number expressed in scientific notation?</span>
C
Hope I helped! :-)
~Sequoyah! :-)
Follow the steps in order how to know how to divide
