We have to set up 2 different equations if we are to solve for 2 unknowns. The first equation is x = y + 4. One number (x) is (=) 4 more than another (y + 4). Since we have determined that x is larger (cuz it's 4 more than y), when we set up their difference, we are going to subtract y from x cuz x is bigger. The second equation then is
. In our first equation we said that x = y + 4, so let's sub that value in for x in the second equation:
. Expand that binomial to get
. Of course the y squared terms cancel each other out leaving us with 8y + 16 = 64. Solving for y we get that y = 6. Subbing 6 in for y in our first equation, x = 6 + 4 tells us that x = 10. Yay!
Answer:
Step by step explanation:
x + 90 = 7x
90 = 7x - x
90 = 6x
x = 90/6
x = 15
Result x = 15
Measure of each angle = 15 + 90
= 105
a) x = 15
b) angle = 105°
Second problem
a= Complementary
b) 90°
c) x = 90 - 37
x = 53°
Answer:
, explanation for how to get there
Step-by-step explanation:
If we have the equation 
, we want to isolate c on one side and find it's value.
Let's first divide both sides by 4.
Now let's solve for the absolute value. We know that:
or
Possibility 1:
Subtract 3c from both sides:
Possibility 2:
Add 4c to both sides:
Subtract 5 from both sides:
Divide both sides by 7:
Plugging both of these values into the equation, we can see that only 5 works.
Hope this helped!
Making cos B the subject;
2acCosB=
cosB=
