T) -7x+10y=20. M) -3x+y=-2 - ,
2(8x-5y)=35(2) -1(x+y)=-6(-)
-7x+10y=20. -3x+y=-2
16x-10y=70. -x-y=6
9x=90. -4x=4
[x=10] [x= -1]
-7(10)+10y=20. -3(-1)+y=-2
-70+10y=20. 3+y=-2
10y=90. [y= -5]
[y=9]
Answer:
31.5cm²
Step-by-step explanation:
area of a triangle =1/2 b h
b= 7cm
h=9cm
1/2×7×9
= 1/2×63
= 31.5cm²
hypotenuse is unknown so,
c²=a²+b²
c²= 7² + 9²
= 49 + 81
c²= 130
c= 11.4cm
perimeter= 7 +9+11.4
=27.4cm
pls note that no unit was stated
Answer:
μ ≈ 2.33
σ ≈ 1.25
Step-by-step explanation:
Each person has equal probability of ⅓.
The mean is the expected value:
μ = E(X) = ∑ X P(X)
μ = (1) (⅓) + (2) (⅓) + (4) (⅓)
μ = ⁷/₃
The standard deviation is:
σ² = ∑ (X−μ)² P(X)
σ² = (1 − ⁷/₃)² (⅓) + (2 − ⁷/₃)² (⅓) + (4 − ⁷/₃)² (⅓)
σ² = ¹⁴/₉
σ ≈ 1.25
Answer:
15 seconds
Step-by-step explanation:
How did i get this answer? It is apparent that the girl is capable of running 6 2/3 metres per one second and she must run 100 metres.
First, let's convert 2/3 into a decimal so that it is easier to calculate later. 2/3=0.667 (you can also just do 2 divide by 3 and will end up with the same number)
Now our numbers are 6.667 and 100. Let's divide 100 by 6.667 which estimates to 15