Answer:
The numbers are -21 and 21
Step-by-step explanation:
Let
x ----> one number
y ----> another number
S----> the sum of their squares
we know that
----> equation A
----> equation B
substitute equation A in equation B
This is the equation of a vertical parabola open upward
The vertex is a minimum
Find the coordinates of the vertex
Using a graphing tool
The vertex is the point (21,882) ----> see the attached figure
we have
x=21
<em>Find the value of y</em>
therefore
The numbers are -21 and 21
Answer:
The value of Mary's investment after two years = £12362.7
Step-by-step explanation:
P = Principal / initial amount
R = rate of interest per cent per year
T = number of years
A = final amount at the end of T years
Then:
A = P*(1 + R/100)^2
In our example:
P = £12000
R = 1.5 per cent per year
T = 2 years
Thus:
A = 12000*(1 + 1.5/100)^2
= 12000*(1 + 0.015)^2
= 12000*(1.015)^2
= 12000*(1.030225)
= 12362.7
Value of investment after two years = £12362.7
Answer:
17.1
Step-by-step explanation:
1. Find the Mean
(25+40+35+25+40+60+75)/7 = 42.9
2.For each number, subtract the Mean and square the result.
(25-42.86)^2=319
(40-42.86)^2=8.2
(35-42.86)^2=61.8
(25-42.86)^2=319
(40-42.86)^2=8.2
(60-42.86)^2=293.8
(75-42.86)^2=1033
3. Find the Mean of those squared differences.
(319+8.2+61.8+319+8.2+293.8+1033)/7=291.9
4.Take the square root of that and this is what you want.
square root of 291.9 = 17.1
USE SUBSTITUTION FOR 3A+4S=57, 2A+8S=86 to find adult=$7 student=$9
CHECK STEP: 3(7)+4(9)=57
21+36=57 TRUE
Answer:
1. (a)4:1 (b)1:81 (c)9:25
2. (a)2:3 (b)4;5 (c)7:16
3. (a)3:5 (b)3:5 (c)9:25
Step-by-step explanation:
1. Given the ratio of similitude of two similar triangles, the ratio of their areas is the <u>square of the ratio of similitude.</u>
(a)2:1
Ratio of Area
(b)1:9
Ratio of Area
(c)3:5
Ratio of Area
2. Given the ratio of the areas of the sides of two similar polygons, the ratio of the sides is the ratio of the square root of their areas.
(a)4:9
Ratio of Sides
(b)16:25
Ratio of Sides
(c)49:256
Ratio of Sides
3.Lengths of the Diameter are 6 and 10.
Diameter = Radius/2
Therefore, their radii are 3 and 5.
(a)Ratio of their Radii =3:5
(b)Since the circumference is still a length, Ratio of their Circumference =3:5
(c)Ratio of their Areas