Question

x=−3, y=2 andz=−5 (a)x×(y+z)=x×y+x×z

Answer 1

Answer:

Given,

x−y+z=5 and x  

2

+y  

2

+z  

2

=49

We know,

(a+b+c)  

2

=a  

2

+b  

2

+c  

2

+2(ab+bc+ca)

Here,

a=x

b=−y

c=z

Thus,

⇒(x−y+z)  

2

=x  

2

+y  

2

+z  

2

+2(−xy−yz+zx)

⇒5  

2

=49+2(−xy−yz+zx)

⇒−2(−xy−yz+zx)=49−25

⇒(−xy−yz+zx)=−  

2

24

​  

 

⇒(−xy−yz+zx)=−12

Step-by-step explanation: