the solution for the following system of equations is (2,1) x+y=10 x-y=4 true or false?

Answer 1

substitute and check

answer is FALSE
_________________

Answer 2

x+y=10
x-y=4
---------
2x=14, x=7
Substituting 7 for x into either original equation gives
7+y=10, y=3
Solution set is (7,3)

There's an easier way: the question is not what the solution is, but true or false- is (2,1) a solution?
Is it was, substituting 2 for x and 1 for y should prove the equality. Thus, in x+y=10, substitution gives
2+1 =10. Not so, therefore answer is false.
Hope this helps

Answer 3

False!!

x - y = 4; x = 4 + y
therefore substituting for x ; 4 + y + y = 10
4 + 2y = 10
2y = 10 - 4 = 6
y = 6/2 = 3
then since y = 3 ; x = 4 + 3 = 7
therefore; x = 7
y = 3

Answer 4

No, because if x+y =10, then 2+1 = 10 and that is false.

Answer 5

False ... here's my explanation

eqn 1 = x+y=10
eqn 2 = x-y=4

re-arrange eqn 2 to make x the subject and call this eqn 3

eqn 3 = x=4+y

substitute eqn 3 into eqn 1: -

x+y=10 becomes (4+y)+y=10
rearrange for y and we find y = 7

sub y=7 into eqn 2 to get
x-y=4 becomes x-(7)=4
rearrange to find x =11.

Now check!

put x=11 and y = 7 into eqn 2

x-y=4 becomes (11)-(7)=4

this is statement holds so .... x=11 and y=7

Answer 6

since 2 is x and 1 is y
substitute
so...
2+1=10
3 = 10
2 is not equal to 10 so it is false...

2-1 = 4
1 = 4
1 is not equal to 4 so it is false...

Answer 7

x+y = 10
x-y = 4 . . adding
2x = 14
x = 7
y = 4 + 7 = 11

answer is false

Answer 8

Adding gives:-
2x = 14
x = 7
3 + y = 10
y = 3
Solution is (7 , 3) thus (2 , 1) is false.

Answer 9

false

x+y=10
so
x=10-y
so
y in (2,1) is 1 and x is 2

x=10-1=9 so its false

then

x-y=4
so
x=4+y
so in turn x=4+1
which is x=5

so x in (2,1) is 2

2 is not equal to five

FALSE

Answer 10

false
because
2x+y = 10x - y = 4 will solve one x,y
1x+y = 10x - y = 4 will solve another x,y

Answer 11

false

the solution is (7, 3)