$\Rightarrow 7x=50-1$

$\Rightarrow 7x=49$

$\Rightarrow x=7$

$2^{4}x-3^{2}x=145-255:51$

$16x-9x=140$

$7x=140$

$x=20$

$(3x+4{)}^2=3^2+2^3+83$

$(3x+4{)}^2=$$9+8+83$

$(3x+4{)}^2=100$

$(3x+4{)}^2={10}^2$

$3x+4=10$

$3x=10-4$

$3x=6$

$x=6:3=2$

$20-\left[7\right(x-3)+4]=2$

$7(x-3)+4=20-2$

$7(x-3)+4=18$

$7(x-3)=18-4$

$7(x-3)=14$

$x-3=14:7$

$x-3=2$

$x=2+3=5$

$2448:[119-(x-6\left)\right]=24$

$199-(x-6)=2448:24$

$199-(x-6)=102$

$x-6=199-102$

$x-6=97$

$x=97+6=103$

1 curly

2 funny

3 long

4 lazy

5 well-built?

6 tall

7 shy

8 handsome

9 friendly

10 intelligent

(6¹⁵ x 6^{2) :} 6⁴ = $6^{15+2}:6^4=6^{17}:6^4=6^{17-4}=6^{13}$

5^3x5=5¹⁵

$a,=25\times (32+92\times 4)$

$=25\times 400$

$=10000$.

$b,=3119(11\times 11-121)$

$=3119\times 0$

$=0$.

$c,=(123+87)(24+76)$

$=200\times 100$

$=20000$.