(a) Add 10 to both sides: $3x = 45$. Divide both sides by 3: $x = 15$. Check: $3(15) - 10 = 45 - 10 = 35$ ✓ (b) Subtract $3s$ from both sides: $5s - 3s = 0$, so $2s = 0$. Divide by 2: $s = 0$. Check: $5(0) = 0$ and $3(0) = 0$ ✓ (c) Subtract $2u$ from both sides: $u - 7 = 3$. Add 7 to both sides: $u = 10$. Check: $3(10) - 7 = 30 - 7 = 23$ and $2(10) + 3 = 23$ ✓ (d) Expand: $4m + 24 - 8 = 2m - 4$. Simplify: $4m + 16 = 2m - 4$. Subtract $2m$: $2m + 16 = -4$. Subtract 16: $2m = -20$. Divide by 2: $m = -10$. Check: $4(-10 + 6) - 8 = 4(-4) - 8 = -16 - 8 = -24$ and $2(-10) - 4 = -20 - 4 = -24$ ✓ (e) Multiply both sides by 15: $u = 6 \times 15 = 90$. Check: $\frac{90}{15} = 6$ ✓