Answer:
d or a
Step-by-step explanation:
50/55/100/105/.................
We have 10 ml of 20% acid to which we need to add "x" milliliters of 100% acid to make 50% acid.
.20 * 10 + 1.00x = .50 * (10 +x)
in which "x" is the volume of the 100% acid to be added.
2 + x = 5 + .5 x
.5x = 3
x = 6 milliliters
Source:
http://www.1728.org/mixture.htm
Scroll down to problem B
Answer:
x(x + 1)
Step-by-step explanation: This is an important way of solving quadratic equations. The first step of factorising an expression is to 'take out' any common factors which the terms have. So if you were asked to factorise x² + x, since x goes into both terms, you would write x(x + 1)
Answer:
The common for the second question is 30
Answer:
4 to 7 and 8 to 14
Step-by-step explanation: