this can be solve by 3 variable equation
let x be the money of luke
y money of rachel
z money of daniel
first equation
x = y + 21
second equation
x = z + 48
third equation
x + y + z = 168
solving simultaneously
x =79
y = 58
z = 31
<span> </span>
Answer:
Step-by-step explanation:
2
x
2
+
8
−
4
x
+
3
x
−
6
x
2
+
7
Subtract
6
x
2
from
2
x
2
.
−
4
x
2
+
8
−
4
x
+
3
x
+
7
Add
8
and
7
.
−
4
x
2
−
4
x
+
3
x
+
15
Add
−
4
x
and
3
x
.
−
4
x
2
−
x
+
15
Answer:
total area = 217 m³
Step-by-step explanation:
area of the triangle
= 14 × 10
= 140 m²
area of a semicircle
= 1/2 × 22/7 × 7 × 7
= 77 m²
total area
= 140 + 77
= 217 m³
Answer:y= -4
Step-by-step explanation:
1 Solve for xx in 7x-4y=-127x−4y=−12.
x=\frac{4(y-3)}{7}
x=
7
4(y−3)
2 Substitute x=\frac{4(y-3)}{7}x=
7
4(y−3)
into 9x-4y=-209x−4y=−20.
\frac{36(y-3)}{7}-4y=-20
7
36(y−3)
−4y=−20
3 Solve for yy in \frac{36(y-3)}{7}-4y=-20
7
36(y−3)
−4y=−20.
y=-4
y=−4
4 Substitute y=-4y=−4 into x=\frac{4(y-3)}{7}x=
7
4(y−3)
.
x=-4
x=−4
5 Therefore,
\begin{aligned}&x=-4\\&y=-4\end{aligned}
x=−4
y=−4
Answer:
B
Step-by-step explanation:
The closed circle at - 
indicates that x can equal this value
The open circle at 
indicates that x cannot equal this value.
All values of x between - and are valid, thus
- ≤ x < → B
