Question

ajuda ai por favor .............

Answer 1

a) x/10 = 3/30

x×30 = 10×3

30x = 30

x = 30÷30

x = 1

b) (x+4)/x = 3/4

(x+4)×4 = x×3

4x+16 = 3x

4x-3x = -16

x = -16

c) (x-2)/x = (2x-1)/(x-2)

(x-2)×(x-2) = x×(2x-1)

x²-4x+4 = 2x²-x

x²-2x²-4x+x+4 = 0

-x²-3x+4 = 0 ×(-1)

x²+3x-4 = 0

Δ = 3²-4×1×(-4)

Δ = 9-4×1×(-4)

Δ = 9-4×(-4)

Δ = 9+16

Δ = 25

x = -3+-\|25/2×1

x = -3+-5/2

x¹ = -3+5/2

x¹ = 2/2

x¹ = 1

x² = -3-5/2

x² = -8/2

x² = -4

x = {1, -4}

d) 20/x = 14/7

20×7 = x×14

140 = 14x

140/14 = x

10 = x