3(x-7)+8=-20
Multiply the bracket by 3
(3)(x)(3(-7)+8= -20
3x-21+8= -20
3x-13= -20
Move -13 to the other side. Sign changes from -13 to +13.
3x-13+13= -20+13
3x= -7
Divide by 3
3x/3= -7/3
x= -7/3 or in mixed number : -2 1/3
Answer : x= -7/3 or in mixed number : -2 1/3
Ok so lets plug in a first -1/3(-3) would equal 9 a is the accurate answer
AK = 640
Δ ABC and ΔFJK are similar. They are small triangles.
ΔCDF is the big triangle.
640 / 2 = 320 m= CF
AC & FK= 320/2 = 160 m each
2AC = CF = 2FK
2(160) = 320 = 2(160)
BG = 20 m
20/160 = x / 320
20*320 = 160x
6400 = 160x
6400/160 = x
40 = x
Area of CDF = (40 m * 320 m)/2 = 12,800 / 2= 6,400 m²