Answer:
D. 15x10^20
Step-by-step explanation:
The rule for scientific notation is that the coefficient has to be between 1 and less than 10. This means there is only one digit in front of the decimal. 15x10^20 should be written as 1.5x10^21 to follow the rule.
Here a right angled triangle given. We know that one angle of a right angled triangle is 90°.
As the sum of three angles of a triangle is 180°, so we can say the sum of other two angles of a right angled triangle is (180-90)° = 90°.
Here in the figure the other two angles given
and
. Sum of these two angles is 90°.
So we can write the equation as,

We have to remove the parenthesis now.

Now we will add the like terms. Here x and 2x are like terms. By adding them we will get,

To solve it for x, now we have to move 15 to the other side by subtracting it from both sides.



Now to get x, we have to move 3 to the other side, by dividing it to both sides.



We have got the required value of x.
The solution is x= 25.
Answer:
(5r - 20)
Step-by-step explanation:
(3r + 14) + (Ar + B) = (8r - 6)
B = -6 - 14 = -20
A = 8 - 3 = 5
Answer:
Option D RX=4 units
Step-by-step explanation:
we know that
<em>In the right triangle RTS</em>
The cosine of angle TRS is equal to
cos(TRS)=RT/RS
substitute
cos(TRS)=6/9 -----> equation A
<em>In the right triangle RTX</em>
The cosine of angle TRX is equal to
cos(TRX)=RX/RT
substitute
cos(TRX)=RX/6 -----> equation B
∠TRS=∠TRX -----> is the same angle
Match equation A and equation B
6/9=RX/6
RX=6*6/9=4 units