Let p be the prize of a pen and m the prize of a mechanical pencils. If you buy six pens and one mechanical pencil, you spend 6p+m. We know that this equals 9, because you get 1$ change from a 10$ bill.
Similarly, if you buy four pens and two mechanical pencils, you spend 4p+2m, which is 8$, because now you get a $2 change. Put these equation together in a system:

Now, if you multiply the first equation by 2, the system becomes

Subtract the second equation from the first:

Plug this value into the first equation to get

Answer:
6.9 foot.
Step-by-step explanation:
Given: Length of lamp post= 12-foot.
The angle of elevation of the sun is 60°.
∴ The length of Lamp post, which is opposite is 12-foot.
Now, finding the length of shadow cast by foot lamp.
Length of shadow is adjacent.
∴ We know the formula for
= 
Next, putting the value in the formula.
⇒ 
Cross multiplying both side and using the value of Tan 60°
∴ Adjacent=
≅ 6.9 (nearest tenth value)
6.9 is the length of shadow cast by a 12-foot lamp post.
The slope of the line given its equation is calculated through, m = -A / B. The slope of the given line is 4/3. The line perpendicular to it has the slope of -3/4. The slope-point form of the equation is,
y - y1 = m(x - x1)
where m is the slope and x1 and y1 the abscissa and ordinate of the point, respectively.
Substituting the values above,
y --2 = (-3/4)(x - 3)
Simplifying the equation gives 3x + 4y = 1.
Answer:
3-3 -4-3=0
Step-by-step explanation:
just divide 3-3 and -4-1 and u get your answer