Answer:
BC = [tex] 1.8 [/tex]
Step-by-step explanation:
∆ABC is an equilateral ∆ because all three angles are equal. Therefore, all its sides would be equal also. This means AB = BC = AC
Thus, let's find the value of x.
[tex] \frac{7}{4}x - 1 = \frac{9}{3}x - 3 [/tex]
Collect like terms
[tex] \frac{7}{4}x - \frac{9}{3}x = 1 - 3 [/tex]
[tex] \frac{7x}{4} - 3x = -2 [/tex]
[tex] \frac{7x - 12x}{4} = -2 [/tex]
[tex] \frac{-5x}{4} = -2 [/tex]
Multiply both sides by 4
[tex] \frac{-5x}{4}*4 = -2*4 [/tex]
[tex] -5x = -8 [/tex]
Divide both sides by -5
[tex] x = \frac{8}{5} [/tex]
AB = BC = AC
Therefore,
BC = [tex] \frac{7}{4}x - 1 [/tex]
Plug in the value of x
BC = [tex] \frac{7}{4}*\frac{8}{5} - 1 [/tex]
BC = [tex] \frac{56}{20} - 1 [/tex]
BC = [tex] 2.8 - 1 [/tex]
BC = [tex] 1.8 [/tex]
