The answer is 13 minus 3 equals 10
Let the x ml of water be mixed with 237 ml of ammonia whose strength is 100%, in order to create a mixture of 75% strength.
The equation required to solve this will be:
237/(237+x)=75/100
solving for x we get:
237/(237+x)=3/4
237×4=3(237+x)
948=711+3x
3x+711=948
3x=948-711
3x=237
x=237/3
x=79 ml
therefore the amount of water to be added will be 79 ml
Answer:
ok im done what is this free points
Step-by-step explanation:
Answer:
45.6° (1 d.p)
Step-by-step explanation:
Using the cosine rule;
c = √( a² + b² - 2ab Cosx)
11 =√(8² + 15² - 2 (8) (15) Cosx)
11² = 8² + 15² - 240 Cosx
11² - 8² - 15² = - 240 Cosx
-168 = -240 cosx
cosx = 0.7
x = cos⁻¹ (0.7) = 45.57 ≈ 45.6°