`a)`$\sqrt{64x+64}$ `-`$\sqrt{25x+25}$ `+ `$\sqrt{4x+4}$ `=20` `b)` $\sqrt{3x}$ `+5`$\sqrt{27x}$ `-16=` $\sqrt{432x}$
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`a)\sqrt{64x+64}-\sqrt{25x+25}+\sqrt{4x+4}=20`
`<=>\sqrt{64(x+1)}-\sqrt{25(x+1)}+\sqrt{4(x+1)}=20`
`<=>8\sqrt{x+1}-5\sqrt{x+1}+2\sqrt{x+1}=20`
`<=>5\sqrt{x+1}=20`
`<=>\sqrt{x+1}=4`
`<=>x+1=16`
`<=>x=15`
`b)\sqrt{3x}+5\sqrt{27x}-16=\sqrt{432x}`
`<=>\sqrt{3x}+5\sqrt{9.3x}-\sqrt{144.3x}=16`
`<=>\sqrt{3x}+5.3.\sqrt{3x}-12\sqrt{3x}=16`
`<=>4\sqrt{3x}=4`
`<=>3x=16`
`<=>x=\frac{16}{3}`