for these you need to rearrange the equations and do substitutions.
#3 = if x+y=5 then you know x = 5-y
now substitute that equation for x in the 2nd one so x + 2y = 8 becomes
5-y + 2y = 8 2y - y becomes 1y which becomes y then subtract 5 from each side to get y =3
now replace y with 3 in the first equation x = 5-3 so x = 2
so (2,3) is the answer
same type of work for #4
2x-y=6 ,S0 y = 2X+6
so now you have 4x+2(2x+6)=-4
that becomes 4x +4x+12 = -4
8x+8 = 1, x =1
y = 2(1)-6 = -4
so answer is (1,-4)
Part A: 0.10x + 0.25 = 0.80 (dimes are 10 cents or 0.10 dollars, quarters are 0.25 dollars)
Part B: Plug in what you DO know and solve the one you DON’T:
0.10x + 0.25(2) = 0.80
0.10x + 0.50 = 0.80. Subtract 0.50 from both sides:
0.10x = 0.30 (Divide both sides by 0.10)
x = 3
Therefore you have 3 dimes
Answer:
In solid geometry, a face is a flat (planar) surface that forms part of the boundary of a solid object; a three-dimensional solid bounded exclusively by faces is a polyhedron. (OR) A face is a 2D shape that makes up one surface of a 3D shape, an edge is where two faces meet and a vertex is the point or corner of a geometric shape.
Step-by-step explanation:
Ask every fifth person that exits the school
(systematic random)
