1.
√(16+20)=√36=6
C
2.
√(21-9)=√(12)=(√4)(√3)=2√3
B
3. 2*√3=2*1.73205=3.464
B
1.C
2.B
3.B
Answer:
1+1 = 2
Step-by-step explanation:
Answer:
2500 pence (C = 2500)
Step-by-step explanation:
From the given information, t is the number of texts so essentially you will plug in the number of texts provided (150) in the place of the variable t.
Apply the same thing to minutes, plug in the number of minutes (50) in the place of the variable m.
Now multiply the substitutes with the co-efficient.
(10*150=1500 & 20*50=1000)
Add the addends
C = 2500
0.362 in expanded form is 0.3 + 0.06 + 0.002
Assume that the amount needed from the 5% solution is x and that the amount needed from the 65% solution is y.
We are given that, the final solution should be 42 ml, this means that:
x + y = 42 ...........> equation I
This can also be written as:
x = 42-y .......> equation II
We are also given that the final concentration should be 45%, this means that:
5% x + 65% y = 45% (x+y)
0.05x + 0.65y = 0.45(x+y)
We have x+y = 42 from equation I, therefore:
0.05x + 0.65y = 0.45(42)
0.05x + 0.65y = 18.9 .........> equation III
Substitute with equation II in equation III as follows:
0.05x + 0.65y = 18.9
0.05(42-y) + 0.65y = 18.9
2.1 - 0.05y + 0.65y = 18.9
0.6y = 18.9 - 2.1
0.6y = 16.8
y = 28 ml
Substitute with y in equation II to get x as follows:
x = 42-y
x = 42 - 28
x = 14 ml
Based on the above calculations:
amount of 5% solution = x = 14 ml
amount of 65% solution = y = 28 ml
The correct choice is:
The teacher will need 14 mL of the 5% solution and 28 mL of the 65% solution.
