add $t0 $zero ,$zero
loop: beq $a1,$zero,finish
add $t0,$t0,$a0 //$t0=$t0+$a0
sub $a1,$a1,1
j loop
finish:addi $t0,$t0,100 //a=b+100
add $v0,$zero

write the equivalent c language code snippets as comments.

i have tried a bit but i not the answer correct a not

How about posting your attempt.

Rather than just describing to us rather unconvincingly that you've made any attempt at all.

We get a lot of "I tried but it didn't work, here's my question, can you do it for me, kthxbye" types.