first you turn the fractions into inproper fractions by multiplying the whole number by the denomonator and adding the numerator
4×4=16
16+3=19
19/4
4×7=28
28+1=29
29/7
keep the denomonators the same. now that you've converted them into inproper fractions you can multiply them
19/4 × 29/7=551/28
there is no way to simplify this answer so this is the final answer
Y = 5 - 4x
5 - 4x = x^2 - 2x - 19
0 = x^2 + 2x -24
0 = (x + 6)(x - 4)
Therefore x = -6 (Given) or 4
x = 4, y = -9
(4,-9) is the other solution

Actually Welcome to the Concept of the Equilateral Triangles.
Since, we know that, all the sides of a triangle are equal, hence it is a Equilateral triangle.
Equilateral triangle has one all angles equal to 60°.
so, major angle P = 60°
hence, 2x=60°
===> x = 30°
A)24 boards/1 * 47.5 inch/boards * 1 ft/12in = 95 ft.
according to dimensional analysis the answer is 95 ft.
b) 95/8 is approximately 12 so 12 boards are needed.
What’s the subject?
20 characters really???