Answer:
Step-by-step explanation:
The ratio of boys to girls is
7
:
11
, and there are
49
boys, so therefore there are
49
7
⋅
11
=
77
girls
Total number of boys and girls in the classroom is
77
+
49
=
126
.
Answer:
Original angle = 122*
Supplementary angle = 58*
Step-by-step explanation:
A supplementary angle is one of two angles that make up 180*
If one angle is 30*, its supplementary angle is 150*. 30 + 150 = 180.
So in this case we have two angles, the original and the supplementary angle. The original angle is 64* more than the supplementary angle. The key word is MORE.
The formula to figure it out would look like this: x + (x + 64) = 180
x is the supplementary angle
x + 64 is the original angle (64 MORE than its supplementary angle)
180 is the total measure of the two angles because they are supplementary and we know that supplementary angles always equals 180* when added together.
Take the formula and do a little algebra.
x + (x + 64) = 180
Subtract 64 from both sides
x + x = 116
Combine the x's
2x = 116
Divide both side by 2
x = 58
Remeber we know that the original angle is 64 more than the supplementary angle, so we'll add the 64 to the value of x and we get 122.
x + 64 = 122
Check our work:
x + (x + 64) = 180
58 + 58 + 64 = 180
The sum of all 3 angles is 180 degrees, you should be able to solve from here.
Answer:
b²+3.5a+8.4b
Step-by-step explanation:
Given the expression
3b^2 + 2(a+5.4b) -2.4b + 1.5a - 2b^2
Expand
3b^2 + 2a+10.8b -2.4b + 1.5a - 2b^2
Collect the like terms
= 3b²-2b²+2a+1.5a+10.8b-2.4b
= b²+3.5a+8.4b
Hence the equivalent expression is b²+3.5a+8.4b
<span>Standard deviation for mean of n objects = (square root n) x s.d. for one
object.
So you need (2.8/0.5)^2 or around 32.</span>
