Answer:

Step-by-step explanation:

<u>Multiply both sides by 7:</u>


<u>Subtract 4 from both sides:</u>


<u>Divide both sides by 10:</u>


_____________________
Answer:
what grade are you in that seems hard
Step-by-step explanation:
Answer:
1. 3, and 2. m x n
Step-by-step explanation:
1. for an upper triangular 2x2 matrix i.e. (a,0,c,d), three (03) unknown elements a, c, and d are needed to be specified.
2. for m x n matrix, m*n elements are needed to be specified.
The last one.................