pls solve the maths for me i will give bainliest. i need it due today.

Answer:
x = 41 || surface area = 8950 cm³
Step-by-step explanation:
1)
[tex]c^{2}=u^{2}+z^{2}- \frac{6x}{y+4u}[/tex]
[tex]-u^{2}-z^{2}+c^{2}=- \frac{6x}{y+4u}[/tex]
[tex]+u^{2}+z^{2}-c^{2}=\frac{6x}{y+4u}[/tex]
[tex]({y+4u})(+u^{2}+z^{2}-c^{2})={6x}[/tex]
[tex]\frac{({y+4u})(+u^{2}+z^{2}-c^{2})}{6} =x[/tex]
[tex]x =\frac{(10+4(-1))((-1)^{2}+7^{2}-(-3)^{2} ) }{6}[/tex]
[tex]x=41[/tex]
2)
Formula of surface area of cuboid:
2(lh + lw+ hw) square units
2(60*25+60*35+25*35)
2(4475)
8950 cm³