Answer:

Step-by-step explanation:

.8 (88%)+.2x=90%
70.4%+.2x=90%
subtract 70.4% from 90% to get 19.6%
make the .2x into 2 and the 19.6 into 196
divide 196 by 2 to come up with the answer of 98%.
you will need a 98% to have a 90% for the final grade
Answer:
Step-by-step explanation:
base=42 m
height=h=?
base angle θ=60°
tan 60=h/42
h=42tan 60=42√3≈72.75 m
height of taller building=135+42√3 m≈135+72.75≈207.75 m≈208 m
Since the second equation gives a value for a, we can substitute it into the other equation to find a value for B.
Let's substitute b-2 into the first equation wherever there is an a.
a - 3b = 4
(b-2) - 3b = 4
b - 2 - 3b = 4
-2 - 2b = 4
-2b = 6
b = -3
Now let's find a by substituting -3 into either of the equations to find the value of a.
a = b - 2
a = -3 - 2
a = -5
So your solution set is (-5, -3)