Answer:
Complementary angles.
Step-by-step explanation:
Notice that
and
, by given.
, by sum of angles.
, by supplementary angles definition.

Which means,

Therefore,
, in other words, angles a and b are complementary by definition.
Answer:
x = 19
Step-by-step explanation:
The two angles with measures are supplementary.
6x + 9 + 4x - 19 = 180
10x - 10 = 180
10x = 190
x = 19
36. If 7/11 did bring one, then 4/11 didn't. 4*9=36
Answer:
- <em>0.75</em><em> liters of 5% hydrochloric acid solution </em>
- <em>0.25</em><em> liters of 45% hydrochloric acid solution.</em>
Step-by-step explanation:
Let us assume that, x liters of the 5% hydrochloric acid and y liters of the 45% hydrochloric acid solutions are combined.
As Rajan need total of 1 liter of solution, so
i.e
--------------------1
As Rajan needs 5% hydrochloric acid and 45% hydrochloric acid to make a 1 liter batch of 15% hydrochloric acid, hence acid content of the mixture of two acids will be same as of the final one, so

i.e
-------------2
Putting value of x from equation 1 in equation 2,





Putting the value of y in equation 1,

Therefore, Rajan must use 0.75 liters of 5% hydrochloric acid solution and 0.25 liters of 45% hydrochloric acid solution.