Answer:
11. [tex]500z^{2} +400z+80[/tex]
12. [tex]704a^2 + 1344a + 640[/tex]
13. [tex]160y^2 + 44zy^2 + z^2y^2[/tex]
Step-by-step explanation:
11. [tex](50z + 20)(10z + 4) = ?[/tex]
Using Formula:
[tex](a+b) (c+d) = a(c+d)+b(c+d)[/tex]
[tex]50z(10z+4) + 20(10z + 4) = \\\Rightarrow 500z^{2} + 200 z+200z+80\\\Rightarrow 500z^{2} +400z+80[/tex]
12. [tex](88a + 80)(8a + 8) = ?[/tex]
Using Formula:
[tex](a+b) (c+d) = a(c+d)+b(c+d)[/tex]
[tex]\Rightarrow 88a(8a+8) + 80(8a + 8)\\\Rightarrow 704a^2 + 704a + 640a + 640\\\Rightarrow 704a^2 + 1344a + 640[/tex]
13. [tex](40y + zy)(4y + zy) = ?[/tex]
Using Formula:
[tex](a+b) (c+d) = a(c+d)+b(c+d)[/tex]
[tex]\Rightarrow 40y(4y + zy) + zy(4y + zy)\\\Rightarrow 160y^2 + 40zy^2 + 4y^2z + z^2y^2\\\Rightarrow 160y^2 + 44zy^2 + z^2y^2\\[/tex]
