Answer:
20 nickels and 26 dimes
Step-by-step explanation:
- She has $3.60 in nickels and dimes
- a nickel is $0.05 and a dime is $0.10
- let n be the number of nickels and d be the number of dimes
- thus the first equation is 3.6 = 0.05n +0.1d
- If she has 46 coins then n + d = 46
- then n = 46 - d
- sub n = 46 - d into 3.6 = 0.05n +0.1d
- 3.6 = 0.05(46 - d) + 0.1d
- 3.6 = 2.3 -0.05d+0.1d
- 1.3 = 0.05d
- 26 = d
- sub d = 26 into n+d=46
- n+26=46
- n=20
- Check by subbing n=20 and d=26 into 0.05n +0.1d
- 0.05(20) +0.1(26)
- 1+2.6 = 3.6
3x+(x-2)=10
4x=12
x=12/4=3
y=x-2=3-2=1
so, x=3 and y=1
Answer: (3;1)
Explanation:
first find the slope m of the line passing through the
the 2 given points
to calculate the slope m use the
gradient formula
∙
x
m
=
y
2
−
y
1
x
2
−
x
1
let
(
x
1
,
y
1
)
=
(
1
,
3
)
and
(
x
2
,
y
2
)
=
(
−
5
,
6
)
m
=
6
−
3
−
5
−
1
=
3
−
6
=
−
1
2
given a line with slope m then the slope of a line
perpendicular to it is
∙
x
m
perpendicular
=
−
1
m
hence
m
perpendicular
=
−
1
−
1
2
=
2
the equation of a line in
slope-intercept form
is.
∙
x
y
=
m
x
+
b
where m is the slope and b the y-intercept
here
m
=
2
y
=
2
x
+
b
←
is the partial equation
to find b substitute
(
−
2
,
7
)
into the partial equation
7
=
−
4
+
b
⇒
b
=
7
+
4
=
11
y
=
2
x
+
11
←
is the required equation
Answer:
the answer is a=6π ~~~~~~~~~~~~~~~~
