1. Length is 14 cm
2. Length is 20.4 cm
3. Not completely sure about 3
(Sorry hope this helps)
3x + 1 = y
2x + 3y = 14
To solve this system of equations, we are going to use the substitution method. Substitution the equation where the variable is isolated into the second equation. In this system of equations, y is isolated, so we will replace y in the second equation with 3x + 1.
2x + 3y = 14
2x + 3(3x + 1) = 14
2x + 9x + 3 = 14
We will add the like terms and subtract 3 from both sides of the equation.
11x + 3 = 14
11x = 11
x = 1
In this system of equations, x is equal to 1. Now we will go back and solve for y, plugging in 1 for x.
3(1) + 1 = y
2(1) + 3y = 14
3 + 1 = y
2 + 3y = 14
4 = y
3y = 2
4 = y
4 = y
The solution to this system of equations is (1, 4).
Answer:
Let C be the position of a person in a helicopter. A,B be two objects lying opposite to each other on either bank of a river.
Let AD=x,BD=y
In ΔACD,
⇒tan30
o
=
AD
CD
⇒
3
1
=
x
700
⇒x=130
3
⇒x=130(1.732)=1212.4
∴ the width of the river =x+y
=1212.4+130
=1342.4m
Step-by-step explanation:
