Answer:
b = 5
Step-by-step explanation:
89b = 411 + 34 (445)
89b = 445
b = 5
Answer:
that is really so difficult ? what do you not understand here ? please let me know, if you need any further explanations.
you know what the perimeter is ? if it's the circumference, the way around the object. in other words, the distance you have to walk, when going along all sidelines of the object.
so the perimeter is the sum of of all side lengths.
56 = x - 1 + 3x + 3x + 1 = 7x
x = 8
that gives us the side lengths :
x - 1 = 7 cm
3x = 21 cm
3x + 1 = 22 cm
the formula for the area of a triangle
A = baseline × height / 2
the advantage of a right-angled triangle in this regard is that the sides enclosing the 90 degree angle are already "acting" as baseline and the height (standing on the baseline with a 90 degree angle).
so, we can simply say here, the 3x side is the baseline, and the x-1 side is also the height.
therefore,
A = 21×7/2 = 147/2 = 73.5 cm²
Answer:
10
Step-by-step explanation:
Let c = sum of ages of all children.
mean age of all children = c/15 = 7
c = 15 * 7 = 105
The sum of the ages of all children is 105.
Let b = sum of ages of the 9 boys.
mean age of boys = b/9 = 5
b = 9 * 5 = 45
The sum of the ages of the boys is 45.
The sum of the ages of the girls is c - b.
c - b = 105 - 45 = 60
The number of girls is 15 - 9 = 6
mean age of girls = (sum of ages of the girls)/(number of girls) =
= 60/6 = 10
6 + (10 x 2) = 26 = (12+1)*2
The answer is it is yes, it is sometimes true, y can =0
