Diagonal of a Rhombus are perpendicular & intersects in their middle point: Assume the diagonals intersects in H
A(0,-8), B(1,-0), C(8,-4) & D(x, y) are the vertices of the rhombus and we have to calculate D(x, y)
Consider the diagonal AC. Find the coordinate (x₁, y₁) H, the middle of AC Coordinate (x₁, y₁) of H, middle of A(0,-8), C(8,-4) x₁ (0+8)/2 & y₁=(-8-4)/2 ==> H(4, -6) Now let's calculate again the coordinate of H, middle of the diagonal BD B(1,-0), D(x, y) x value = (1+x)/2 & y value=(y+0)/2 ==> x= (1+x)/2 & y=y/2 (1+x)/2 & y/2 are the coordinate of the center H, already calculated, then: H(4, -6) = [(1+x)/2 , y/2]==>(1+x)/2 =4 ==> x=7 & y/2 = -6 ==> y= -12
The answer is $162 you take the prices of what she bought and add them together which is $73+$38+$64=$180 then you subtract the $180 from $342 which is $342-$180=$162 so the answer is $162
The letter "x" is often used in algebra to mean a value that is not yet known. It is called a "variable" or sometimes an "unknown". In x + 2 = 7, x is a variable, but we can work out its value if we try!