Answer:
The value of [tex]a[/tex] is 3.
Step-by-step explanation:
Let be [tex]\vec a = \langle a, 5 \rangle[/tex] and [tex]\vec b = \langle -4,-3 \rangle[/tex], the difference between the two vectors is:
[tex]\vec c = \vec b - \vec a[/tex]
[tex]\vec c = \langle a, 5\rangle - \langle -4,-3 \rangle[/tex]
[tex]\vec c = \langle a+4,8 \rangle[/tex]
If we know that [tex]\vec c = \langle 7,8 \rangle[/tex], the value of [tex]a[/tex] is:
[tex]\langle 7, 8 \rangle = \langle a+4, 8\rangle[/tex]
In which,
[tex]a + 4 = 7[/tex]
[tex]a = 3[/tex]
The value of [tex]a[/tex] is 3.